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diff --git a/doc/manual/release-notes.xml b/doc/manual/release-notes.xml new file mode 100644 index 000000000000..37bb730f4063 --- /dev/null +++ b/doc/manual/release-notes.xml @@ -0,0 +1,2272 @@ +<article xmlns="http://docbook.org/ns/docbook" + xmlns:xlink="http://www.w3.org/1999/xlink" + xml:id="sec-relnotes"> + +<title>Nix Release Notes</title> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.7"><title>Release 1.7 (TBA)</title> + +<para>This release has the following changes:</para> + +<itemizedlist> + + <listitem> + <para>New built-in function: <function>builtins.toJSON</function>, + which returns a JSON representation of a value.</para> + </listitem> + + <listitem><para><command>nix-setuid-helper</command> is + gone.</para></listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.6.1"><title>Release 1.6.1 (October 28, 2013)</title> + +<para>This is primarily a bug fix release. Changes of interest +are:</para> + +<itemizedlist> + + <listitem> + <para>Nix 1.6 accidentally changed the semantics of antiquoted + paths in strings, such as <literal>"${/foo}/bar"</literal>. This + release reverts to the Nix 1.5.3 behaviour.</para> + </listitem> + + <listitem> + <para>Previously, Nix optimised expressions such as + <literal>"${<replaceable>expr</replaceable>}"</literal> to + <replaceable>expr</replaceable>. Thus it neither checked whether + <replaceable>expr</replaceable> could be coerced to a string, nor + applied such coercions. This meant that + <literal>"${123}"</literal> evaluatued to <literal>123</literal>, + and <literal>"${./foo}"</literal> evaluated to + <literal>./foo</literal> (even though + <literal>"${./foo} "</literal> evaluates to + <literal>"/nix/store/<replaceable>hash</replaceable>-foo "</literal>). + Nix now checks the type of antiquoted expressions and + applies coercions.</para> + </listitem> + + <listitem> + <para>Nix now shows the exact position of undefined variables. In + particular, undefined variable errors in a <literal>with</literal> + previously didn't show <emphasis>any</emphasis> position + information, so this makes it a lot easier to fix such + errors.</para> + </listitem> + + <listitem> + <para>Undefined variables are now treated consistently. + Previously, the <function>tryEval</function> function would catch + undefined variables inside a <literal>with</literal> but not + outside. Now <function>tryEval</function> never catches undefined + variables.</para> + </listitem> + + <listitem> + <para>Bash completion in <command>nix-shell</command> now works + correctly.</para> + </listitem> + + <listitem> + <para>Stack traces are less verbose: they no longer show calls to + builtin functions and only show a single line for each derivation + on the call stack.</para> + </listitem> + + <listitem> + <para>New built-in function: <function>builtins.typeOf</function>, + which returns the type of its argument as a string.</para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.6.0"><title>Release 1.6 (September 10, 2013)</title> + +<para>In addition to the usual bug fixes, this release has several new +features:</para> + +<itemizedlist> + + <listitem> + <para>The command <command>nix-build --run-env</command> has been + renamed to <command>nix-shell</command>.</para> + </listitem> + + <listitem> + <para><command>nix-shell</command> now sources + <filename>$stdenv/setup</filename> <emphasis>inside</emphasis> the + interactive shell, rather than in a parent shell. This ensures + that shell functions defined by <literal>stdenv</literal> can be + used in the interactive shell.</para> + </listitem> + + <listitem> + <para><command>nix-shell</command> has a new flag + <option>--pure</option> to clear the environment, so you get an + environment that more closely corresponds to the “real” Nix build. + </para> + </listitem> + + <listitem> + <para><command>nix-shell</command> now sets the shell prompt + (<envar>PS1</envar>) to ensure that Nix shells are distinguishable + from your regular shells.</para> + </listitem> + + <listitem> + <para><command>nix-env</command> no longer requires a + <literal>*</literal> argument to match all packages, so + <literal>nix-env -qa</literal> is equivalent to <literal>nix-env + -qa '*'</literal>.</para> + </listitem> + + <listitem> + <para><command>nix-env -i</command> has a new flag + <option>--remove-all</option> (<option>-r</option>) to remove all + previous packages from the profile. This makes it easier to do + declarative package management similar to NixOS’s + <option>environment.systemPackages</option>. For instance, if you + have a specification <filename>my-packages.nix</filename> like this: + +<programlisting> +with import <nixpkgs> {}; +[ thunderbird + geeqie + ... +] +</programlisting> + + then after any change to this file, you can run: + +<screen> +$ nix-env -f my-packages.nix -ir +</screen> + + to update your profile to match the specification.</para> + </listitem> + + <listitem> + <para>The ‘<literal>with</literal>’ language construct is now more + lazy. It only evaluates its argument if a variable might actually + refer to an attribute in the argument. For instance, this now + works: + +<programlisting> +let + pkgs = with pkgs; { foo = "old"; bar = foo; } // overrides; + overrides = { foo = "new"; }; +in pkgs.bar +</programlisting> + + This evaluates to <literal>"new"</literal>, while previously it + gave an “infinite recursion” error.</para> + </listitem> + + <listitem> + <para>Nix now has proper integer arithmetic operators. For + instance, you can write <literal>x + y</literal> instead of + <literal>builtins.add x y</literal>, or <literal>x < + y</literal> instead of <literal>builtins.lessThan x y</literal>. + The comparison operators also work on strings.</para> + </listitem> + + <listitem> + <para>On 64-bit systems, Nix integers are now 64 bits rather than + 32 bits.</para> + </listitem> + + <listitem> + <para>When using the Nix daemon, the <command>nix-daemon</command> + worker process now runs on the same CPU as the client, on systems + that support setting CPU affinity. This gives a significant speedup + on some systems.</para> + </listitem> + + <listitem> + <para>If a stack overflow occurs in the Nix evaluator, you now get + a proper error message (rather than “Segmentation fault”) on some + systems.</para> + </listitem> + + <listitem> + <para>In addition to directories, you can now bind-mount regular + files in chroots through the (now misnamed) option + <option>build-chroot-dirs</option>.</para> + </listitem> + +</itemizedlist> + +<para>This release has contributions from Domen Kožar, Eelco Dolstra, +Florian Friesdorf, Gergely Risko, Ivan Kozik, Ludovic Courtès and Shea +Levy.</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.5.3"><title>Release 1.5.3 (June 17, 2013)</title> + +<para>This is primarily a bug fix release. The following changes are +noteworthy:</para> + +<itemizedlist> + + <listitem> + <para>Yet another security bug involving hard links to files + outside the store was fixed. This bug only affected multi-user + installations that do not have hard link restrictions + enabled. (NixOS is thus not vulnerable.)</para> + </listitem> + + <listitem> + <para>The default binary cache URL has changed from + <uri>http://nixos.org/binary-cache</uri> to + <uri>http://cache.nixos.org</uri>. The latter is hosted on Amazon + CloudFront (courtesy of <link + xlink:href="http://www.logicblox.com/">LogicBlox</link>) and + should provide better performance for users in both Europe and + North America.</para> + </listitem> + + <listitem> + <para>The binary cache substituter now prints a warning message if + fetching information from the cache takes more than five seconds. + Thus network or server problems no longer make Nix appear to just + hang.</para> + </listitem> + + <listitem> + <para>Stack traces now show function names, e.g. +<screen> +while evaluating `concatMapStrings' at `<replaceable>...</replaceable>/nixpkgs/pkgs/lib/strings.nix:18:25': +</screen> + Also, if a function is called with an unexpected argument, Nix + now shows the name of the argument. + </para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.5.2"><title>Release 1.5.2 (May 13, 2013)</title> + +<para>This is primarily a bug fix release. It has contributions from +Eelco Dolstra, Lluís Batlle i Rossell and Shea Levy.</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.5.1"><title>Release 1.5.1 (February 28, 2013)</title> + +<para>The bug fix to the bug fix had a bug itself, of course. But +this time it will work for sure!</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.5"><title>Release 1.5 (February 27, 2013)</title> + +<para>This is a brown paper bag release to fix a regression introduced +by the hard link security fix in 1.4.</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.4"><title>Release 1.4 (February 26, 2013)</title> + +<para>This release fixes a security bug in multi-user operation. It +was possible for derivations to cause the mode of files outside of the +Nix store to be changed to 444 (read-only but world-readable) by +creating hard links to those files (<link +xlink:href="https://github.com/NixOS/nix/commit/5526a282b5b44e9296e61e07d7d2626a79141ac4">details</link>).</para> + +<para>There are also the following improvements:</para> + +<itemizedlist> + + <listitem><para>New built-in function: + <function>builtins.hashString</function>.</para></listitem> + + <listitem><para>Build logs are now stored in + <filename>/nix/var/log/nix/drvs/<replaceable>XX</replaceable>/</filename>, + where <replaceable>XX</replaceable> is the first two characters of + the derivation. This is useful on machines that keep a lot of build + logs (such as Hydra servers).</para></listitem> + + <listitem><para>The function <function>corepkgs/fetchurl</function> + can now make the downloaded file executable. This will allow + getting rid of all bootstrap binaries in the Nixpkgs source + tree.</para></listitem> + + <listitem><para>Language change: The expression <literal>"${./path} + ..."</literal> now evaluates to a string instead of a + path.</para></listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.3"><title>Release 1.3 (January 4, 2013)</title> + +<para>This is primarily a bug fix release. When this version is first +run on Linux, it removes any immutable bits from the Nix store and +increases the schema version of the Nix store. (The previous release +removed support for setting the immutable bit; this release clears any +remaining immutable bits to make certain operations more +efficient.)</para> + +<para>This release has contributions from Eelco Dolstra and Stuart +Pernsteiner.</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.2"><title>Release 1.2 (December 6, 2012)</title> + +<para>This release has the following improvements and changes:</para> + +<itemizedlist> + + <listitem> + <para>Nix has a new binary substituter mechanism: the + <emphasis>binary cache</emphasis>. A binary cache contains + pre-built binaries of Nix packages. Whenever Nix wants to build a + missing Nix store path, it will check a set of binary caches to + see if any of them has a pre-built binary of that path. The + configuration setting <option>binary-caches</option> contains a + list of URLs of binary caches. For instance, doing +<screen> +$ nix-env -i thunderbird --option binary-caches http://cache.nixos.org +</screen> + will install Thunderbird and its dependencies, using the available + pre-built binaries in <uri>http://cache.nixos.org</uri>. + The main advantage over the old “manifest”-based method of getting + pre-built binaries is that you don’t have to worry about your + manifest being in sync with the Nix expressions you’re installing + from; i.e., you don’t need to run <command>nix-pull</command> to + update your manifest. It’s also more scalable because you don’t + need to redownload a giant manifest file every time. + </para> + + <para>A Nix channel can provide a binary cache URL that will be + used automatically if you subscribe to that channel. If you use + the Nixpkgs or NixOS channels + (<uri>http://nixos.org/channels</uri>) you automatically get the + cache <uri>http://cache.nixos.org</uri>.</para> + + <para>Binary caches are created using <command>nix-push</command>. + For details on the operation and format of binary caches, see the + <command>nix-push</command> manpage. More details are provided in + <link xlink:href="http://lists.science.uu.nl/pipermail/nix-dev/2012-September/009826.html">this + nix-dev posting</link>.</para> + </listitem> + + <listitem> + <para>Multiple output support should now be usable. A derivation + can declare that it wants to produce multiple store paths by + saying something like +<programlisting> +outputs = [ "lib" "headers" "doc" ]; +</programlisting> + This will cause Nix to pass the intended store path of each output + to the builder through the environment variables + <literal>lib</literal>, <literal>headers</literal> and + <literal>doc</literal>. Other packages can refer to a specific + output by referring to + <literal><replaceable>pkg</replaceable>.<replaceable>output</replaceable></literal>, + e.g. +<programlisting> +buildInputs = [ pkg.lib pkg.headers ]; +</programlisting> + If you install a package with multiple outputs using + <command>nix-env</command>, each output path will be symlinked + into the user environment.</para> + </listitem> + + <listitem> + <para>Dashes are now valid as part of identifiers and attribute + names.</para> + </listitem> + + <listitem> + <para>The new operation <command>nix-store --repair-path</command> + allows corrupted or missing store paths to be repaired by + redownloading them. <command>nix-store --verify --check-contents + --repair</command> will scan and repair all paths in the Nix + store. Similarly, <command>nix-env</command>, + <command>nix-build</command>, <command>nix-instantiate</command> + and <command>nix-store --realise</command> have a + <option>--repair</option> flag to detect and fix bad paths by + rebuilding or redownloading them.</para> + </listitem> + + <listitem> + <para>Nix no longer sets the immutable bit on files in the Nix + store. Instead, the recommended way to guard the Nix store + against accidental modification on Linux is to make it a read-only + bind mount, like this: + +<screen> +$ mount --bind /nix/store /nix/store +$ mount -o remount,ro,bind /nix/store +</screen> + + Nix will automatically make <filename>/nix/store</filename> + writable as needed (using a private mount namespace) to allow + modifications.</para> + </listitem> + + <listitem> + <para>Store optimisation (replacing identical files in the store + with hard links) can now be done automatically every time a path + is added to the store. This is enabled by setting the + configuration option <literal>auto-optimise-store</literal> to + <literal>true</literal> (disabled by default).</para> + </listitem> + + <listitem> + <para>Nix now supports <command>xz</command> compression for NARs + in addition to <command>bzip2</command>. It compresses about 30% + better on typical archives and decompresses about twice as + fast.</para> + </listitem> + + <listitem> + <para>Basic Nix expression evaluation profiling: setting the + environment variable <envar>NIX_COUNT_CALLS</envar> to + <literal>1</literal> will cause Nix to print how many times each + primop or function was executed.</para> + </listitem> + + <listitem> + <para>New primops: <varname>concatLists</varname>, + <varname>elem</varname>, <varname>elemAt</varname> and + <varname>filter</varname>.</para> + </listitem> + + <listitem> + <para>The command <command>nix-copy-closure</command> has a new + flag <option>--use-substitutes</option> (<option>-s</option>) to + download missing paths on the target machine using the substitute + mechanism.</para> + </listitem> + + <listitem> + <para>The command <command>nix-worker</command> has been renamed + to <command>nix-daemon</command>. Support for running the Nix + worker in “slave” mode has been removed.</para> + </listitem> + + <listitem> + <para>The <option>--help</option> flag of every Nix command now + invokes <command>man</command>.</para> + </listitem> + + <listitem> + <para>Chroot builds are now supported on systemd machines.</para> + </listitem> + +</itemizedlist> + +<para>This release has contributions from Eelco Dolstra, Florian +Friesdorf, Mats Erik Andersson and Shea Levy.</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.1"><title>Release 1.1 (July 18, 2012)</title> + +<para>This release has the following improvements:</para> + +<itemizedlist> + + <listitem> + <para>On Linux, when doing a chroot build, Nix now uses various + namespace features provided by the Linux kernel to improve + build isolation. Namely: + <itemizedlist> + <listitem><para>The private network namespace ensures that + builders cannot talk to the outside world (or vice versa): each + build only sees a private loopback interface. This also means + that two concurrent builds can listen on the same port (e.g. as + part of a test) without conflicting with each + other.</para></listitem> + <listitem><para>The PID namespace causes each build to start as + PID 1. Processes outside of the chroot are not visible to those + on the inside. On the other hand, processes inside the chroot + <emphasis>are</emphasis> visible from the outside (though with + different PIDs).</para></listitem> + <listitem><para>The IPC namespace prevents the builder from + communicating with outside processes using SysV IPC mechanisms + (shared memory, message queues, semaphores). It also ensures + that all IPC objects are destroyed when the builder + exits.</para></listitem> + <listitem><para>The UTS namespace ensures that builders see a + hostname of <literal>localhost</literal> rather than the actual + hostname.</para></listitem> + <listitem><para>The private mount namespace was already used by + Nix to ensure that the bind-mounts used to set up the chroot are + cleaned up automatically.</para></listitem> + </itemizedlist> + </para> + </listitem> + + <listitem> + <para>Build logs are now compressed using + <command>bzip2</command>. The command <command>nix-store + -l</command> decompresses them on the fly. This can be disabled + by setting the option <literal>build-compress-log</literal> to + <literal>false</literal>.</para> + </listitem> + + <listitem> + <para>The creation of build logs in + <filename>/nix/var/log/nix/drvs</filename> can be disabled by + setting the new option <literal>build-keep-log</literal> to + <literal>false</literal>. This is useful, for instance, for Hydra + build machines.</para> + </listitem> + + <listitem> + <para>Nix now reserves some space in + <filename>/nix/var/nix/db/reserved</filename> to ensure that the + garbage collector can run successfully if the disk is full. This + is necessary because SQLite transactions fail if the disk is + full.</para> + </listitem> + + <listitem> + <para>Added a basic <function>fetchurl</function> function. This + is not intended to replace the <function>fetchurl</function> in + Nixpkgs, but is useful for bootstrapping; e.g., it will allow us + to get rid of the bootstrap binaries in the Nixpkgs source tree + and download them instead. You can use it by doing + <literal>import <nix/fetchurl.nix> { url = + <replaceable>url</replaceable>; sha256 = + "<replaceable>hash</replaceable>"; }</literal>. (Shea Levy)</para> + </listitem> + + <listitem> + <para>Improved RPM spec file. (Michel Alexandre Salim)</para> + </listitem> + + <listitem> + <para>Support for on-demand socket-based activation in the Nix + daemon with <command>systemd</command>.</para> + </listitem> + + <listitem> + <para>Added a manpage for + <citerefentry><refentrytitle>nix.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> + </listitem> + + <listitem> + <para>When using the Nix daemon, the <option>-s</option> flag in + <command>nix-env -qa</command> is now much faster.</para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-1.0"><title>Release 1.0 (May 11, 2012)</title> + +<para>There have been numerous improvements and bug fixes since the +previous release. Here are the most significant:</para> + +<itemizedlist> + + <listitem> + <para>Nix can now optionally use the Boehm garbage collector. + This significantly reduces the Nix evaluator’s memory footprint, + especially when evaluating large NixOS system configurations. It + can be enabled using the <option>--enable-gc</option> configure + option.</para> + </listitem> + + <listitem> + <para>Nix now uses SQLite for its database. This is faster and + more flexible than the old <emphasis>ad hoc</emphasis> format. + SQLite is also used to cache the manifests in + <filename>/nix/var/nix/manifests</filename>, resulting in a + significant speedup.</para> + </listitem> + + <listitem> + <para>Nix now has an search path for expressions. The search path + is set using the environment variable <envar>NIX_PATH</envar> and + the <option>-I</option> command line option. In Nix expressions, + paths between angle brackets are used to specify files that must + be looked up in the search path. For instance, the expression + <literal><nixpkgs/default.nix></literal> looks for a file + <filename>nixpkgs/default.nix</filename> relative to every element + in the search path.</para> + </listitem> + + <listitem> + <para>The new command <command>nix-build --run-env</command> + builds all dependencies of a derivation, then starts a shell in an + environment containing all variables from the derivation. This is + useful for reproducing the environment of a derivation for + development.</para> + </listitem> + + <listitem> + <para>The new command <command>nix-store --verify-path</command> + verifies that the contents of a store path have not + changed.</para> + </listitem> + + <listitem> + <para>The new command <command>nix-store --print-env</command> + prints out the environment of a derivation in a format that can be + evaluated by a shell.</para> + </listitem> + + <listitem> + <para>Attribute names can now be arbitrary strings. For instance, + you can write <literal>{ "foo-1.2" = …; "bla bla" = …; }."bla + bla"</literal>.</para> + </listitem> + + <listitem> + <para>Attribute selection can now provide a default value using + the <literal>or</literal> operator. For instance, the expression + <literal>x.y.z or e</literal> evaluates to the attribute + <literal>x.y.z</literal> if it exists, and <literal>e</literal> + otherwise.</para> + </listitem> + + <listitem> + <para>The right-hand side of the <literal>?</literal> operator can + now be an attribute path, e.g., <literal>attrs ? + a.b.c</literal>.</para> + </listitem> + + <listitem> + <para>On Linux, Nix will now make files in the Nix store immutable + on filesystems that support it. This prevents accidental + modification of files in the store by the root user.</para> + </listitem> + + <listitem> + <para>Nix has preliminary support for derivations with multiple + outputs. This is useful because it allows parts of a package to + be deployed and garbage-collected separately. For instance, + development parts of a package such as header files or static + libraries would typically not be part of the closure of an + application, resulting in reduced disk usage and installation + time.</para> + </listitem> + + <listitem> + <para>The Nix store garbage collector is faster and holds the + global lock for a shorter amount of time.</para> + </listitem> + + <listitem> + <para>The option <option>--timeout</option> (corresponding to the + configuration setting <literal>build-timeout</literal>) allows you + to set an absolute timeout on builds — if a build runs for more than + the given number of seconds, it is terminated. This is useful for + recovering automatically from builds that are stuck in an infinite + loop but keep producing output, and for which + <literal>--max-silent-time</literal> is ineffective.</para> + </listitem> + + <listitem> + <para>Nix development has moved to GitHub (<link + xlink:href="https://github.com/NixOS/nix" />).</para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-0.16"><title>Release 0.16 (August 17, 2010)</title> + +<para>This release has the following improvements:</para> + +<itemizedlist> + + <listitem> + <para>The Nix expression evaluator is now much faster in most + cases: typically, <link + xlink:href="http://www.mail-archive.com/nix-dev@cs.uu.nl/msg04113.html">3 + to 8 times compared to the old implementation</link>. It also + uses less memory. It no longer depends on the ATerm + library.</para> + </listitem> + + <listitem> + <para> + Support for configurable parallelism inside builders. Build + scripts have always had the ability to perform multiple build + actions in parallel (for instance, by running <command>make -j + 2</command>), but this was not desirable because the number of + actions to be performed in parallel was not configurable. Nix + now has an option <option>--cores + <replaceable>N</replaceable></option> as well as a configuration + setting <varname>build-cores = + <replaceable>N</replaceable></varname> that causes the + environment variable <envar>NIX_BUILD_CORES</envar> to be set to + <replaceable>N</replaceable> when the builder is invoked. The + builder can use this at its discretion to perform a parallel + build, e.g., by calling <command>make -j + <replaceable>N</replaceable></command>. In Nixpkgs, this can be + enabled on a per-package basis by setting the derivation + attribute <varname>enableParallelBuilding</varname> to + <literal>true</literal>. + </para> + </listitem> + + <listitem> + <para><command>nix-store -q</command> now supports XML output + through the <option>--xml</option> flag.</para> + </listitem> + + <listitem> + <para>Several bug fixes.</para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-0.15"><title>Release 0.15 (March 17, 2010)</title> + +<para>This is a bug-fix release. Among other things, it fixes +building on Mac OS X (Snow Leopard), and improves the contents of +<filename>/etc/passwd</filename> and <filename>/etc/group</filename> +in <literal>chroot</literal> builds.</para> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-0.14"><title>Release 0.14 (February 4, 2010)</title> + +<para>This release has the following improvements:</para> + +<itemizedlist> + + <listitem> + <para>The garbage collector now starts deleting garbage much + faster than before. It no longer determines liveness of all paths + in the store, but does so on demand.</para> + </listitem> + + <listitem> + <para>Added a new operation, <command>nix-store --query + --roots</command>, that shows the garbage collector roots that + directly or indirectly point to the given store paths.</para> + </listitem> + + <listitem> + <para>Removed support for converting Berkeley DB-based Nix + databases to the new schema.</para> + </listitem> + + <listitem> + <para>Removed the <option>--use-atime</option> and + <option>--max-atime</option> garbage collector options. They were + not very useful in practice.</para> + </listitem> + + <listitem> + <para>On Windows, Nix now requires Cygwin 1.7.x.</para> + </listitem> + + <listitem> + <para>A few bug fixes.</para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-0.13"><title>Release 0.13 (November 5, +2009)</title> + +<para>This is primarily a bug fix release. It has some new +features:</para> + +<itemizedlist> + + <listitem> + <para>Syntactic sugar for writing nested attribute sets. Instead of + +<programlisting> +{ + foo = { + bar = 123; + xyzzy = true; + }; + a = { b = { c = "d"; }; }; +} +</programlisting> + + you can write + +<programlisting> +{ + foo.bar = 123; + foo.xyzzy = true; + a.b.c = "d"; +} +</programlisting> + + This is useful, for instance, in NixOS configuration files.</para> + + </listitem> + + <listitem> + <para>Support for Nix channels generated by Hydra, the Nix-based + continuous build system. (Hydra generates NAR archives on the + fly, so the size and hash of these archives isn’t known in + advance.)</para> + </listitem> + + <listitem> + <para>Support <literal>i686-linux</literal> builds directly on + <literal>x86_64-linux</literal> Nix installations. This is + implemented using the <function>personality()</function> syscall, + which causes <command>uname</command> to return + <literal>i686</literal> in child processes.</para> + </listitem> + + <listitem> + <para>Various improvements to the <literal>chroot</literal> + support. Building in a <literal>chroot</literal> works quite well + now.</para> + </listitem> + + <listitem> + <para>Nix no longer blocks if it tries to build a path and another + process is already building the same path. Instead it tries to + build another buildable path first. This improves + parallelism.</para> + </listitem> + + <listitem> + <para>Support for large (> 4 GiB) files in NAR archives.</para> + </listitem> + + <listitem> + <para>Various (performance) improvements to the remote build + mechanism.</para> + </listitem> + + <listitem> + <para>New primops: <varname>builtins.addErrorContext</varname> (to + add a string to stack traces — useful for debugging), + <varname>builtins.isBool</varname>, + <varname>builtins.isString</varname>, + <varname>builtins.isInt</varname>, + <varname>builtins.intersectAttrs</varname>.</para> + </listitem> + + <listitem> + <para>OpenSolaris support (Sander van der Burg).</para> + </listitem> + + <listitem> + <para>Stack traces are no longer displayed unless the + <option>--show-trace</option> option is used.</para> + </listitem> + + <listitem> + <para>The scoping rules for <literal>inherit + (<replaceable>e</replaceable>) ...</literal> in recursive + attribute sets have changed. The expression + <replaceable>e</replaceable> can now refer to the attributes + defined in the containing set.</para> + </listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-0.12"><title>Release 0.12 (November 20, +2008)</title> + +<itemizedlist> + + <listitem> + <para>Nix no longer uses Berkeley DB to store Nix store metadata. + The principal advantages of the new storage scheme are: it works + properly over decent implementations of NFS (allowing Nix stores + to be shared between multiple machines); no recovery is needed + when a Nix process crashes; no write access is needed for + read-only operations; no more running out of Berkeley DB locks on + certain operations.</para> + + <para>You still need to compile Nix with Berkeley DB support if + you want Nix to automatically convert your old Nix store to the + new schema. If you don’t need this, you can build Nix with the + <filename>configure</filename> option + <option>--disable-old-db-compat</option>.</para> + + <para>After the automatic conversion to the new schema, you can + delete the old Berkeley DB files: + + <screen> +$ cd /nix/var/nix/db +$ rm __db* log.* derivers references referrers reserved validpaths DB_CONFIG</screen> + + The new metadata is stored in the directories + <filename>/nix/var/nix/db/info</filename> and + <filename>/nix/var/nix/db/referrer</filename>. Though the + metadata is stored in human-readable plain-text files, they are + not intended to be human-editable, as Nix is rather strict about + the format.</para> + + <para>The new storage schema may or may not require less disk + space than the Berkeley DB environment, mostly depending on the + cluster size of your file system. With 1 KiB clusters (which + seems to be the <literal>ext3</literal> default nowadays) it + usually takes up much less space.</para> + </listitem> + + <listitem><para>There is a new substituter that copies paths + directly from other (remote) Nix stores mounted somewhere in the + filesystem. For instance, you can speed up an installation by + mounting some remote Nix store that already has the packages in + question via NFS or <literal>sshfs</literal>. The environment + variable <envar>NIX_OTHER_STORES</envar> specifies the locations of + the remote Nix directories, + e.g. <literal>/mnt/remote-fs/nix</literal>.</para></listitem> + + <listitem><para>New <command>nix-store</command> operations + <option>--dump-db</option> and <option>--load-db</option> to dump + and reload the Nix database.</para></listitem> + + <listitem><para>The garbage collector has a number of new options to + allow only some of the garbage to be deleted. The option + <option>--max-freed <replaceable>N</replaceable></option> tells the + collector to stop after at least <replaceable>N</replaceable> bytes + have been deleted. The option <option>--max-links + <replaceable>N</replaceable></option> tells it to stop after the + link count on <filename>/nix/store</filename> has dropped below + <replaceable>N</replaceable>. This is useful for very large Nix + stores on filesystems with a 32000 subdirectories limit (like + <literal>ext3</literal>). The option <option>--use-atime</option> + causes store paths to be deleted in order of ascending last access + time. This allows non-recently used stuff to be deleted. The + option <option>--max-atime <replaceable>time</replaceable></option> + specifies an upper limit to the last accessed time of paths that may + be deleted. For instance, + + <screen> + $ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")</screen> + + deletes everything that hasn’t been accessed in two months.</para></listitem> + + <listitem><para><command>nix-env</command> now uses optimistic + profile locking when performing an operation like installing or + upgrading, instead of setting an exclusive lock on the profile. + This allows multiple <command>nix-env -i / -u / -e</command> + operations on the same profile in parallel. If a + <command>nix-env</command> operation sees at the end that the profile + was changed in the meantime by another process, it will just + restart. This is generally cheap because the build results are + still in the Nix store.</para></listitem> + + <listitem><para>The option <option>--dry-run</option> is now + supported by <command>nix-store -r</command> and + <command>nix-build</command>.</para></listitem> + + <listitem><para>The information previously shown by + <option>--dry-run</option> (i.e., which derivations will be built + and which paths will be substituted) is now always shown by + <command>nix-env</command>, <command>nix-store -r</command> and + <command>nix-build</command>. The total download size of + substitutable paths is now also shown. For instance, a build will + show something like + + <screen> +the following derivations will be built: + /nix/store/129sbxnk5n466zg6r1qmq1xjv9zymyy7-activate-configuration.sh.drv + /nix/store/7mzy971rdm8l566ch8hgxaf89x7lr7ik-upstart-jobs.drv + ... +the following paths will be downloaded/copied (30.02 MiB): + /nix/store/4m8pvgy2dcjgppf5b4cj5l6wyshjhalj-samba-3.2.4 + /nix/store/7h1kwcj29ip8vk26rhmx6bfjraxp0g4l-libunwind-0.98.6 + ...</screen> + + </para></listitem> + + <listitem><para>Language features: + + <itemizedlist> + + <listitem><para>@-patterns as in Haskell. For instance, in a + function definition + + <programlisting>f = args @ {x, y, z}: <replaceable>...</replaceable>;</programlisting> + + <varname>args</varname> refers to the argument as a whole, which + is further pattern-matched against the attribute set pattern + <literal>{x, y, z}</literal>.</para></listitem> + + <listitem><para>“<literal>...</literal>” (ellipsis) patterns. + An attribute set pattern can now say <literal>...</literal> at + the end of the attribute name list to specify that the function + takes <emphasis>at least</emphasis> the listed attributes, while + ignoring additional attributes. For instance, + + <programlisting>{stdenv, fetchurl, fuse, ...}: <replaceable>...</replaceable></programlisting> + + defines a function that accepts any attribute set that includes + at least the three listed attributes.</para></listitem> + + <listitem><para>New primops: + <varname>builtins.parseDrvName</varname> (split a package name + string like <literal>"nix-0.12pre12876"</literal> into its name + and version components, e.g. <literal>"nix"</literal> and + <literal>"0.12pre12876"</literal>), + <varname>builtins.compareVersions</varname> (compare two version + strings using the same algorithm that <command>nix-env</command> + uses), <varname>builtins.length</varname> (efficiently compute + the length of a list), <varname>builtins.mul</varname> (integer + multiplication), <varname>builtins.div</varname> (integer + division). + <!-- <varname>builtins.genericClosure</varname> --> + </para></listitem> + + </itemizedlist> + + </para></listitem> + + <listitem><para><command>nix-prefetch-url</command> now supports + <literal>mirror://</literal> URLs, provided that the environment + variable <envar>NIXPKGS_ALL</envar> points at a Nixpkgs + tree.</para></listitem> + + <listitem><para>Removed the commands + <command>nix-pack-closure</command> and + <command>nix-unpack-closure</command>. You can do almost the same + thing but much more efficiently by doing <literal>nix-store --export + $(nix-store -qR <replaceable>paths</replaceable>) > closure</literal> and + <literal>nix-store --import < + closure</literal>.</para></listitem> + + <listitem><para>Lots of bug fixes, including a big performance bug in + the handling of <literal>with</literal>-expressions.</para></listitem> + +</itemizedlist> + +</section> + + +<!--==================================================================--> + +<section xml:id="ssec-relnotes-0.11"><title>Release 0.11 (December 31, +2007)</title> + +<para>Nix 0.11 has many improvements over the previous stable release. +The most important improvement is secure multi-user support. It also +features many usability enhancements and language extensions, many of +them prompted by NixOS, the purely functional Linux distribution based +on Nix. Here is an (incomplete) list:</para> + + +<itemizedlist> + + + <listitem><para>Secure multi-user support. A single Nix store can + now be shared between multiple (possible untrusted) users. This is + an important feature for NixOS, where it allows non-root users to + install software. The old setuid method for sharing a store between + multiple users has been removed. Details for setting up a + multi-user store can be found in the manual.</para></listitem> + + + <listitem><para>The new command <command>nix-copy-closure</command> + gives you an easy and efficient way to exchange software between + machines. It copies the missing parts of the closure of a set of + store path to or from a remote machine via + <command>ssh</command>.</para></listitem> + + + <listitem><para>A new kind of string literal: strings between double + single-quotes (<literal>''</literal>) have indentation + “intelligently” removed. This allows large strings (such as shell + scripts or configuration file fragments in NixOS) to cleanly follow + the indentation of the surrounding expression. It also requires + much less escaping, since <literal>''</literal> is less common in + most languages than <literal>"</literal>.</para></listitem> + + + <listitem><para><command>nix-env</command> <option>--set</option> + modifies the current generation of a profile so that it contains + exactly the specified derivation, and nothing else. For example, + <literal>nix-env -p /nix/var/nix/profiles/browser --set + firefox</literal> lets the profile named + <filename>browser</filename> contain just Firefox.</para></listitem> + + + <listitem><para><command>nix-env</command> now maintains + meta-information about installed packages in profiles. The + meta-information is the contents of the <varname>meta</varname> + attribute of derivations, such as <varname>description</varname> or + <varname>homepage</varname>. The command <literal>nix-env -q --xml + --meta</literal> shows all meta-information.</para></listitem> + + + <listitem><para><command>nix-env</command> now uses the + <varname>meta.priority</varname> attribute of derivations to resolve + filename collisions between packages. Lower priority values denote + a higher priority. For instance, the GCC wrapper package and the + Binutils package in Nixpkgs both have a file + <filename>bin/ld</filename>, so previously if you tried to install + both you would get a collision. Now, on the other hand, the GCC + wrapper declares a higher priority than Binutils, so the former’s + <filename>bin/ld</filename> is symlinked in the user + environment.</para></listitem> + + + <listitem><para><command>nix-env -i / -u</command>: instead of + breaking package ties by version, break them by priority and version + number. That is, if there are multiple packages with the same name, + then pick the package with the highest priority, and only use the + version if there are multiple packages with the same + priority.</para> + + <para>This makes it possible to mark specific versions/variant in + Nixpkgs more or less desirable than others. A typical example would + be a beta version of some package (e.g., + <literal>gcc-4.2.0rc1</literal>) which should not be installed even + though it is the highest version, except when it is explicitly + selected (e.g., <literal>nix-env -i + gcc-4.2.0rc1</literal>).</para></listitem> + + + <listitem><para><command>nix-env --set-flag</command> allows meta + attributes of installed packages to be modified. There are several + attributes that can be usefully modified, because they affect the + behaviour of <command>nix-env</command> or the user environment + build script: + + <itemizedlist> + + <listitem><para><varname>meta.priority</varname> can be changed + to resolve filename clashes (see above).</para></listitem> + + <listitem><para><varname>meta.keep</varname> can be set to + <literal>true</literal> to prevent the package from being + upgraded or replaced. Useful if you want to hang on to an older + version of a package.</para></listitem> + + <listitem><para><varname>meta.active</varname> can be set to + <literal>false</literal> to “disable” the package. That is, no + symlinks will be generated to the files of the package, but it + remains part of the profile (so it won’t be garbage-collected). + Set it back to <literal>true</literal> to re-enable the + package.</para></listitem> + + </itemizedlist> + + </para></listitem> + + + <listitem><para><command>nix-env -q</command> now has a flag + <option>--prebuilt-only</option> (<option>-b</option>) that causes + <command>nix-env</command> to show only those derivations whose + output is already in the Nix store or that can be substituted (i.e., + downloaded from somewhere). In other words, it shows the packages + that can be installed “quickly”, i.e., don’t need to be built from + source. The <option>-b</option> flag is also available in + <command>nix-env -i</command> and <command>nix-env -u</command> to + filter out derivations for which no pre-built binary is + available.</para></listitem> + + + <listitem><para>The new option <option>--argstr</option> (in + <command>nix-env</command>, <command>nix-instantiate</command> and + <command>nix-build</command>) is like <option>--arg</option>, except + that the value is a string. For example, <literal>--argstr system + i686-linux</literal> is equivalent to <literal>--arg system + \"i686-linux\"</literal> (note that <option>--argstr</option> + prevents annoying quoting around shell arguments).</para></listitem> + + + <listitem><para><command>nix-store</command> has a new operation + <option>--read-log</option> (<option>-l</option>) + <parameter>paths</parameter> that shows the build log of the given + paths.</para></listitem> + + + <!-- + <listitem><para>TODO: semantic cleanups of string concatenation + etc. (mostly in r6740).</para></listitem> + --> + + + <listitem><para>Nix now uses Berkeley DB 4.5. The database is + upgraded automatically, but you should be careful not to use old + versions of Nix that still use Berkeley DB 4.4.</para></listitem> + + + <!-- foo + <listitem><para>TODO: option <option>- -reregister</option> in + <command>nix-store - -register-validity</command>.</para></listitem> + --> + + + <listitem><para>The option <option>--max-silent-time</option> + (corresponding to the configuration setting + <literal>build-max-silent-time</literal>) allows you to set a + timeout on builds — if a build produces no output on + <literal>stdout</literal> or <literal>stderr</literal> for the given + number of seconds, it is terminated. This is useful for recovering + automatically from builds that are stuck in an infinite + loop.</para></listitem> + + + <listitem><para><command>nix-channel</command>: each subscribed + channel is its own attribute in the top-level expression generated + for the channel. This allows disambiguation (e.g. <literal>nix-env + -i -A nixpkgs_unstable.firefox</literal>).</para></listitem> + + + <listitem><para>The substitutes table has been removed from the + database. This makes operations such as <command>nix-pull</command> + and <command>nix-channel --update</command> much, much + faster.</para></listitem> + + + <listitem><para><command>nix-pull</command> now supports + bzip2-compressed manifests. This speeds up + channels.</para></listitem> + + + <listitem><para><command>nix-prefetch-url</command> now has a + limited form of caching. This is used by + <command>nix-channel</command> to prevent unnecessary downloads when + the channel hasn’t changed.</para></listitem> + + + <listitem><para><command>nix-prefetch-url</command> now by default + computes the SHA-256 hash of the file instead of the MD5 hash. In + calls to <function>fetchurl</function> you should pass the + <literal>sha256</literal> attribute instead of + <literal>md5</literal>. You can pass either a hexadecimal or a + base-32 encoding of the hash.</para></listitem> + + + <listitem><para>Nix can now perform builds in an automatically + generated “chroot”. This prevents a builder from accessing stuff + outside of the Nix store, and thus helps ensure purity. This is an + experimental feature.</para></listitem> + + + <listitem><para>The new command <command>nix-store + --optimise</command> reduces Nix store disk space usage by finding + identical files in the store and hard-linking them to each other. + It typically reduces the size of the store by something like + 25-35%.</para></listitem> + + + <listitem><para><filename>~/.nix-defexpr</filename> can now be a + directory, in which case the Nix expressions in that directory are + combined into an attribute set, with the file names used as the + names of the attributes. The command <command>nix-env + --import</command> (which set the + <filename>~/.nix-defexpr</filename> symlink) is + removed.</para></listitem> + + + <listitem><para>Derivations can specify the new special attribute + <varname>allowedReferences</varname> to enforce that the references + in the output of a derivation are a subset of a declared set of + paths. For example, if <varname>allowedReferences</varname> is an + empty list, then the output must not have any references. This is + used in NixOS to check that generated files such as initial ramdisks + for booting Linux don’t have any dependencies.</para></listitem> + + + <listitem><para>The new attribute + <varname>exportReferencesGraph</varname> allows builders access to + the references graph of their inputs. This is used in NixOS for + tasks such as generating ISO-9660 images that contain a Nix store + populated with the closure of certain paths.</para></listitem> + + + <listitem><para>Fixed-output derivations (like + <function>fetchurl</function>) can define the attribute + <varname>impureEnvVars</varname> to allow external environment + variables to be passed to builders. This is used in Nixpkgs to + support proxy configuration, among other things.</para></listitem> + + + <listitem><para>Several new built-in functions: + <function>builtins.attrNames</function>, + <function>builtins.filterSource</function>, + <function>builtins.isAttrs</function>, + <function>builtins.isFunction</function>, + <function>builtins.listToAttrs</function>, + <function>builtins.stringLength</function>, + <function>builtins.sub</function>, + <function>builtins.substring</function>, + <function>throw</function>, + <function>builtins.trace</function>, + <function>builtins.readFile</function>.</para></listitem> + + +</itemizedlist> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.10.1 (October 11, 2006)</title> + +<para>This release fixes two somewhat obscure bugs that occur when +evaluating Nix expressions that are stored inside the Nix store +(<literal>NIX-67</literal>). These do not affect most users.</para> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.10 (October 6, 2006)</title> + +<note><para>This version of Nix uses Berkeley DB 4.4 instead of 4.3. +The database is upgraded automatically, but you should be careful not +to use old versions of Nix that still use Berkeley DB 4.3. In +particular, if you use a Nix installed through Nix, you should run + +<screen> +$ nix-store --clear-substitutes</screen> + +first.</para></note> + +<warning><para>Also, the database schema has changed slighted to fix a +performance issue (see below). When you run any Nix 0.10 command for +the first time, the database will be upgraded automatically. This is +irreversible.</para></warning> + +<itemizedlist> + + + <!-- Usability / features --> + + + <listitem><para><command>nix-env</command> usability improvements: + + <itemizedlist> + + <listitem><para>An option <option>--compare-versions</option> + (or <option>-c</option>) has been added to <command>nix-env + --query</command> to allow you to compare installed versions of + packages to available versions, or vice versa. An easy way to + see if you are up to date with what’s in your subscribed + channels is <literal>nix-env -qc \*</literal>.</para></listitem> + + <listitem><para><literal>nix-env --query</literal> now takes as + arguments a list of package names about which to show + information, just like <option>--install</option>, etc.: for + example, <literal>nix-env -q gcc</literal>. Note that to show + all derivations, you need to specify + <literal>\*</literal>.</para></listitem> + + <listitem><para><literal>nix-env -i + <replaceable>pkgname</replaceable></literal> will now install + the highest available version of + <replaceable>pkgname</replaceable>, rather than installing all + available versions (which would probably give collisions) + (<literal>NIX-31</literal>).</para></listitem> + + <listitem><para><literal>nix-env (-i|-u) --dry-run</literal> now + shows exactly which missing paths will be built or + substituted.</para></listitem> + + <listitem><para><literal>nix-env -qa --description</literal> + shows human-readable descriptions of packages, provided that + they have a <literal>meta.description</literal> attribute (which + most packages in Nixpkgs don’t have yet).</para></listitem> + + </itemizedlist> + + </para></listitem> + + + <listitem><para>New language features: + + <itemizedlist> + + <listitem><para>Reference scanning (which happens after each + build) is much faster and takes a constant amount of + memory.</para></listitem> + + <listitem><para>String interpolation. Expressions like + +<programlisting> +"--with-freetype2-library=" + freetype + "/lib"</programlisting> + + can now be written as + +<programlisting> +"--with-freetype2-library=${freetype}/lib"</programlisting> + + You can write arbitrary expressions within + <literal>${<replaceable>...</replaceable>}</literal>, not just + identifiers.</para></listitem> + + <listitem><para>Multi-line string literals.</para></listitem> + + <listitem><para>String concatenations can now involve + derivations, as in the example <code>"--with-freetype2-library=" + + freetype + "/lib"</code>. This was not previously possible + because we need to register that a derivation that uses such a + string is dependent on <literal>freetype</literal>. The + evaluator now properly propagates this information. + Consequently, the subpath operator (<literal>~</literal>) has + been deprecated.</para></listitem> + + <listitem><para>Default values of function arguments can now + refer to other function arguments; that is, all arguments are in + scope in the default values + (<literal>NIX-45</literal>).</para></listitem> + + <!-- + <listitem><para>TODO: domain checks (r5895).</para></listitem> + --> + + <listitem><para>Lots of new built-in primitives, such as + functions for list manipulation and integer arithmetic. See the + manual for a complete list. All primops are now available in + the set <varname>builtins</varname>, allowing one to test for + the availability of primop in a backwards-compatible + way.</para></listitem> + + <listitem><para>Real let-expressions: <literal>let x = ...; + ... z = ...; in ...</literal>.</para></listitem> + + </itemizedlist> + + </para></listitem> + + + <listitem><para>New commands <command>nix-pack-closure</command> and + <command>nix-unpack-closure</command> than can be used to easily + transfer a store path with all its dependencies to another machine. + Very convenient whenever you have some package on your machine and + you want to copy it somewhere else.</para></listitem> + + + <listitem><para>XML support: + + <itemizedlist> + + <listitem><para><literal>nix-env -q --xml</literal> prints the + installed or available packages in an XML representation for + easy processing by other tools.</para></listitem> + + <listitem><para><literal>nix-instantiate --eval-only + --xml</literal> prints an XML representation of the resulting + term. (The new flag <option>--strict</option> forces ‘deep’ + evaluation of the result, i.e., list elements and attributes are + evaluated recursively.)</para></listitem> + + <listitem><para>In Nix expressions, the primop + <function>builtins.toXML</function> converts a term to an XML + representation. This is primarily useful for passing structured + information to builders.</para></listitem> + + </itemizedlist> + + </para></listitem> + + + <listitem><para>You can now unambiguously specify which derivation to + build or install in <command>nix-env</command>, + <command>nix-instantiate</command> and <command>nix-build</command> + using the <option>--attr</option> / <option>-A</option> flags, which + takes an attribute name as argument. (Unlike symbolic package names + such as <literal>subversion-1.4.0</literal>, attribute names in an + attribute set are unique.) For instance, a quick way to perform a + test build of a package in Nixpkgs is <literal>nix-build + pkgs/top-level/all-packages.nix -A + <replaceable>foo</replaceable></literal>. <literal>nix-env -q + --attr</literal> shows the attribute names corresponding to each + derivation.</para></listitem> + + + <listitem><para>If the top-level Nix expression used by + <command>nix-env</command>, <command>nix-instantiate</command> or + <command>nix-build</command> evaluates to a function whose arguments + all have default values, the function will be called automatically. + Also, the new command-line switch <option>--arg + <replaceable>name</replaceable> + <replaceable>value</replaceable></option> can be used to specify + function arguments on the command line.</para></listitem> + + + <listitem><para><literal>nix-install-package --url + <replaceable>URL</replaceable></literal> allows a package to be + installed directly from the given URL.</para></listitem> + + + <listitem><para>Nix now works behind an HTTP proxy server; just set + the standard environment variables <envar>http_proxy</envar>, + <envar>https_proxy</envar>, <envar>ftp_proxy</envar> or + <envar>all_proxy</envar> appropriately. Functions such as + <function>fetchurl</function> in Nixpkgs also respect these + variables.</para></listitem> + + + <listitem><para><literal>nix-build -o + <replaceable>symlink</replaceable></literal> allows the symlink to + the build result to be named something other than + <literal>result</literal>.</para></listitem> + + + <!-- Stability / performance / etc. --> + + + <listitem><para>Platform support: + + <itemizedlist> + + <listitem><para>Support for 64-bit platforms, provided a <link + xlink:href="http://bugzilla.sen.cwi.nl:8080/show_bug.cgi?id=606">suitably + patched ATerm library</link> is used. Also, files larger than 2 + GiB are now supported.</para></listitem> + + <listitem><para>Added support for Cygwin (Windows, + <literal>i686-cygwin</literal>), Mac OS X on Intel + (<literal>i686-darwin</literal>) and Linux on PowerPC + (<literal>powerpc-linux</literal>).</para></listitem> + + <listitem><para>Users of SMP and multicore machines will + appreciate that the number of builds to be performed in parallel + can now be specified in the configuration file in the + <literal>build-max-jobs</literal> setting.</para></listitem> + + </itemizedlist> + + </para></listitem> + + + <listitem><para>Garbage collector improvements: + + <itemizedlist> + + <listitem><para>Open files (such as running programs) are now + used as roots of the garbage collector. This prevents programs + that have been uninstalled from being garbage collected while + they are still running. The script that detects these + additional runtime roots + (<filename>find-runtime-roots.pl</filename>) is inherently + system-specific, but it should work on Linux and on all + platforms that have the <command>lsof</command> + utility.</para></listitem> + + <listitem><para><literal>nix-store --gc</literal> + (a.k.a. <command>nix-collect-garbage</command>) prints out the + number of bytes freed on standard output. <literal>nix-store + --gc --print-dead</literal> shows how many bytes would be freed + by an actual garbage collection.</para></listitem> + + <listitem><para><literal>nix-collect-garbage -d</literal> + removes all old generations of <emphasis>all</emphasis> profiles + before calling the actual garbage collector (<literal>nix-store + --gc</literal>). This is an easy way to get rid of all old + packages in the Nix store.</para></listitem> + + <listitem><para><command>nix-store</command> now has an + operation <option>--delete</option> to delete specific paths + from the Nix store. It won’t delete reachable (non-garbage) + paths unless <option>--ignore-liveness</option> is + specified.</para></listitem> + + </itemizedlist> + + </para></listitem> + + + <listitem><para>Berkeley DB 4.4’s process registry feature is used + to recover from crashed Nix processes.</para></listitem> + + <!-- <listitem><para>TODO: shared stores.</para></listitem> --> + + <listitem><para>A performance issue has been fixed with the + <literal>referer</literal> table, which stores the inverse of the + <literal>references</literal> table (i.e., it tells you what store + paths refer to a given path). Maintaining this table could take a + quadratic amount of time, as well as a quadratic amount of Berkeley + DB log file space (in particular when running the garbage collector) + (<literal>NIX-23</literal>).</para></listitem> + + <listitem><para>Nix now catches the <literal>TERM</literal> and + <literal>HUP</literal> signals in addition to the + <literal>INT</literal> signal. So you can now do a <literal>killall + nix-store</literal> without triggering a database + recovery.</para></listitem> + + <listitem><para><command>bsdiff</command> updated to version + 4.3.</para></listitem> + + <listitem><para>Substantial performance improvements in expression + evaluation and <literal>nix-env -qa</literal>, all thanks to <link + xlink:href="http://valgrind.org/">Valgrind</link>. Memory use has + been reduced by a factor 8 or so. Big speedup by memoisation of + path hashing.</para></listitem> + + <listitem><para>Lots of bug fixes, notably: + + <itemizedlist> + + <listitem><para>Make sure that the garbage collector can run + successfully when the disk is full + (<literal>NIX-18</literal>).</para></listitem> + + <listitem><para><command>nix-env</command> now locks the profile + to prevent races between concurrent <command>nix-env</command> + operations on the same profile + (<literal>NIX-7</literal>).</para></listitem> + + <listitem><para>Removed misleading messages from + <literal>nix-env -i</literal> (e.g., <literal>installing + `foo'</literal> followed by <literal>uninstalling + `foo'</literal>) (<literal>NIX-17</literal>).</para></listitem> + + </itemizedlist> + + </para></listitem> + + <listitem><para>Nix source distributions are a lot smaller now since + we no longer include a full copy of the Berkeley DB source + distribution (but only the bits we need).</para></listitem> + + <listitem><para>Header files are now installed so that external + programs can use the Nix libraries.</para></listitem> + +</itemizedlist> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.9.2 (September 21, 2005)</title> + +<para>This bug fix release fixes two problems on Mac OS X: + +<itemizedlist> + + <listitem><para>If Nix was linked against statically linked versions + of the ATerm or Berkeley DB library, there would be dynamic link + errors at runtime.</para></listitem> + + <listitem><para><command>nix-pull</command> and + <command>nix-push</command> intermittently failed due to race + conditions involving pipes and child processes with error messages + such as <literal>open2: open(GLOB(0x180b2e4), >&=9) failed: Bad + file descriptor at /nix/bin/nix-pull line 77</literal> (issue + <literal>NIX-14</literal>).</para></listitem> + +</itemizedlist> + +</para> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.9.1 (September 20, 2005)</title> + +<para>This bug fix release addresses a problem with the ATerm library +when the <option>--with-aterm</option> flag in +<command>configure</command> was <emphasis>not</emphasis> used.</para> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.9 (September 16, 2005)</title> + +<para>NOTE: this version of Nix uses Berkeley DB 4.3 instead of 4.2. +The database is upgraded automatically, but you should be careful not +to use old versions of Nix that still use Berkeley DB 4.2. In +particular, if you use a Nix installed through Nix, you should run + +<screen> +$ nix-store --clear-substitutes</screen> + +first.</para> + + +<itemizedlist> + + <listitem><para>Unpacking of patch sequences is much faster now + since we no longer do redundant unpacking and repacking of + intermediate paths.</para></listitem> + + <listitem><para>Nix now uses Berkeley DB 4.3.</para></listitem> + + <listitem><para>The <function>derivation</function> primitive is + lazier. Attributes of dependent derivations can mutually refer to + each other (as long as there are no data dependencies on the + <varname>outPath</varname> and <varname>drvPath</varname> attributes + computed by <function>derivation</function>).</para> + + <para>For example, the expression <literal>derivation + attrs</literal> now evaluates to (essentially) + + <programlisting> +attrs // { + type = "derivation"; + outPath = derivation! attrs; + drvPath = derivation! attrs; +}</programlisting> + + where <function>derivation!</function> is a primop that does the + actual derivation instantiation (i.e., it does what + <function>derivation</function> used to do). The advantage is that + it allows commands such as <command>nix-env -qa</command> and + <command>nix-env -i</command> to be much faster since they no longer + need to instantiate all derivations, just the + <varname>name</varname> attribute.</para> + + <para>Also, it allows derivations to cyclically reference each + other, for example, + + <programlisting> +webServer = derivation { + ... + hostName = "svn.cs.uu.nl"; + services = [svnService]; +}; +  +svnService = derivation { + ... + hostName = webServer.hostName; +};</programlisting> + + Previously, this would yield a black hole (infinite recursion).</para> + + </listitem> + + <listitem><para><command>nix-build</command> now defaults to using + <filename>./default.nix</filename> if no Nix expression is + specified.</para></listitem> + + <listitem><para><command>nix-instantiate</command>, when applied to + a Nix expression that evaluates to a function, will call the + function automatically if all its arguments have + defaults.</para></listitem> + + <listitem><para>Nix now uses libtool to build dynamic libraries. + This reduces the size of executables.</para></listitem> + + <listitem><para>A new list concatenation operator + <literal>++</literal>. For example, <literal>[1 2 3] ++ [4 5 + 6]</literal> evaluates to <literal>[1 2 3 4 5 + 6]</literal>.</para></listitem> + + <listitem><para>Some currently undocumented primops to support + low-level build management using Nix (i.e., using Nix as a Make + replacement). See the commit messages for <literal>r3578</literal> + and <literal>r3580</literal>.</para></listitem> + + <listitem><para>Various bug fixes and performance + improvements.</para></listitem> + +</itemizedlist> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.8.1 (April 13, 2005)</title> + +<para>This is a bug fix release.</para> + +<itemizedlist> + + <listitem><para>Patch downloading was broken.</para></listitem> + + <listitem><para>The garbage collector would not delete paths that + had references from invalid (but substitutable) + paths.</para></listitem> + +</itemizedlist> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.8 (April 11, 2005)</title> + +<para>NOTE: the hashing scheme in Nix 0.8 changed (as detailed below). +As a result, <command>nix-pull</command> manifests and channels built +for Nix 0.7 and below will now work anymore. However, the Nix +expression language has not changed, so you can still build from +source. Also, existing user environments continue to work. Nix 0.8 +will automatically upgrade the database schema of previous +installations when it is first run.</para> + +<para>If you get the error message + +<screen> +you have an old-style manifest `/nix/var/nix/manifests/[...]'; please +delete it</screen> + +you should delete previously downloaded manifests: + +<screen> +$ rm /nix/var/nix/manifests/*</screen> + +If <command>nix-channel</command> gives the error message + +<screen> +manifest `http://catamaran.labs.cs.uu.nl/dist/nix/channels/[channel]/MANIFEST' +is too old (i.e., for Nix <= 0.7)</screen> + +then you should unsubscribe from the offending channel +(<command>nix-channel --remove +<replaceable>URL</replaceable></command>; leave out +<literal>/MANIFEST</literal>), and subscribe to the same URL, with +<literal>channels</literal> replaced by <literal>channels-v3</literal> +(e.g., <link +xlink:href='http://catamaran.labs.cs.uu.nl/dist/nix/channels-v3/nixpkgs-unstable' +/>).</para> + +<para>Nix 0.8 has the following improvements: + +<itemizedlist> + + <listitem><para>The cryptographic hashes used in store paths are now + 160 bits long, but encoded in base-32 so that they are still only 32 + characters long (e.g., + <filename>/nix/store/csw87wag8bqlqk7ipllbwypb14xainap-atk-1.9.0</filename>). + (This is actually a 160 bit truncation of a SHA-256 + hash.)</para></listitem> + + <listitem><para>Big cleanups and simplifications of the basic store + semantics. The notion of “closure store expressions” is gone (and + so is the notion of “successors”); the file system references of a + store path are now just stored in the database.</para> + + <para>For instance, given any store path, you can query its closure: + + <screen> +$ nix-store -qR $(which firefox) +... lots of paths ...</screen> + + Also, Nix now remembers for each store path the derivation that + built it (the “deriver”): + + <screen> +$ nix-store -qR $(which firefox) +/nix/store/4b0jx7vq80l9aqcnkszxhymsf1ffa5jd-firefox-1.0.1.drv</screen> + + So to see the build-time dependencies, you can do + + <screen> +$ nix-store -qR $(nix-store -qd $(which firefox))</screen> + + or, in a nicer format: + + <screen> +$ nix-store -q --tree $(nix-store -qd $(which firefox))</screen> + + </para> + + <para>File system references are also stored in reverse. For + instance, you can query all paths that directly or indirectly use a + certain Glibc: + + <screen> +$ nix-store -q --referrers-closure \ + /nix/store/8lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4</screen> + + </para> + + </listitem> + + <listitem><para>The concept of fixed-output derivations has been + formalised. Previously, functions such as + <function>fetchurl</function> in Nixpkgs used a hack (namely, + explicitly specifying a store path hash) to prevent changes to, say, + the URL of the file from propagating upwards through the dependency + graph, causing rebuilds of everything. This can now be done cleanly + by specifying the <varname>outputHash</varname> and + <varname>outputHashAlgo</varname> attributes. Nix itself checks + that the content of the output has the specified hash. (This is + important for maintaining certain invariants necessary for future + work on secure shared stores.)</para></listitem> + + <listitem><para>One-click installation :-) It is now possible to + install any top-level component in Nixpkgs directly, through the web + — see, e.g., <link + xlink:href='http://catamaran.labs.cs.uu.nl/dist/nixpkgs-0.8/' />. + All you have to do is associate + <filename>/nix/bin/nix-install-package</filename> with the MIME type + <literal>application/nix-package</literal> (or the extension + <filename>.nixpkg</filename>), and clicking on a package link will + cause it to be installed, with all appropriate dependencies. If you + just want to install some specific application, this is easier than + subscribing to a channel.</para></listitem> + + <listitem><para><command>nix-store -r + <replaceable>PATHS</replaceable></command> now builds all the + derivations PATHS in parallel. Previously it did them sequentially + (though exploiting possible parallelism between subderivations). + This is nice for build farms.</para></listitem> + + <listitem><para><command>nix-channel</command> has new operations + <option>--list</option> and + <option>--remove</option>.</para></listitem> + + <listitem><para>New ways of installing components into user + environments: + + <itemizedlist> + + <listitem><para>Copy from another user environment: + + <screen> +$ nix-env -i --from-profile .../other-profile firefox</screen> + + </para></listitem> + + <listitem><para>Install a store derivation directly (bypassing the + Nix expression language entirely): + + <screen> +$ nix-env -i /nix/store/z58v41v21xd3...-aterm-2.3.1.drv</screen> + + (This is used to implement <command>nix-install-package</command>, + which is therefore immune to evolution in the Nix expression + language.)</para></listitem> + + <listitem><para>Install an already built store path directly: + + <screen> +$ nix-env -i /nix/store/hsyj5pbn0d9i...-aterm-2.3.1</screen> + + </para></listitem> + + <listitem><para>Install the result of a Nix expression specified + as a command-line argument: + + <screen> +$ nix-env -f .../i686-linux.nix -i -E 'x: x.firefoxWrapper'</screen> + + The difference with the normal installation mode is that + <option>-E</option> does not use the <varname>name</varname> + attributes of derivations. Therefore, this can be used to + disambiguate multiple derivations with the same + name.</para></listitem> + + </itemizedlist></para></listitem> + + <listitem><para>A hash of the contents of a store path is now stored + in the database after a successful build. This allows you to check + whether store paths have been tampered with: <command>nix-store + --verify --check-contents</command>.</para></listitem> + + <listitem> + + <para>Implemented a concurrent garbage collector. It is now + always safe to run the garbage collector, even if other Nix + operations are happening simultaneously.</para> + + <para>However, there can still be GC races if you use + <command>nix-instantiate</command> and <command>nix-store + --realise</command> directly to build things. To prevent races, + use the <option>--add-root</option> flag of those commands.</para> + + </listitem> + + <listitem><para>The garbage collector now finally deletes paths in + the right order (i.e., topologically sorted under the “references” + relation), thus making it safe to interrupt the collector without + risking a store that violates the closure + invariant.</para></listitem> + + <listitem><para>Likewise, the substitute mechanism now downloads + files in the right order, thus preserving the closure invariant at + all times.</para></listitem> + + <listitem><para>The result of <command>nix-build</command> is now + registered as a root of the garbage collector. If the + <filename>./result</filename> link is deleted, the GC root + disappears automatically.</para></listitem> + + <listitem> + + <para>The behaviour of the garbage collector can be changed + globally by setting options in + <filename>/nix/etc/nix/nix.conf</filename>. + + <itemizedlist> + + <listitem><para><literal>gc-keep-derivations</literal> specifies + whether deriver links should be followed when searching for live + paths.</para></listitem> + + <listitem><para><literal>gc-keep-outputs</literal> specifies + whether outputs of derivations should be followed when searching + for live paths.</para></listitem> + + <listitem><para><literal>env-keep-derivations</literal> + specifies whether user environments should store the paths of + derivations when they are added (thus keeping the derivations + alive).</para></listitem> + + </itemizedlist> + + </para></listitem> + + <listitem><para>New <command>nix-env</command> query flags + <option>--drv-path</option> and + <option>--out-path</option>.</para></listitem> + + <listitem><para><command>fetchurl</command> allows SHA-1 and SHA-256 + in addition to MD5. Just specify the attribute + <varname>sha1</varname> or <varname>sha256</varname> instead of + <varname>md5</varname>.</para></listitem> + + <listitem><para>Manual updates.</para></listitem> + +</itemizedlist> + +</para> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.7 (January 12, 2005)</title> + +<itemizedlist> + + <listitem><para>Binary patching. When upgrading components using + pre-built binaries (through nix-pull / nix-channel), Nix can + automatically download and apply binary patches to already installed + components instead of full downloads. Patching is “smart”: if there + is a <emphasis>sequence</emphasis> of patches to an installed + component, Nix will use it. Patches are currently generated + automatically between Nixpkgs (pre-)releases.</para></listitem> + + <listitem><para>Simplifications to the substitute + mechanism.</para></listitem> + + <listitem><para>Nix-pull now stores downloaded manifests in + <filename>/nix/var/nix/manifests</filename>.</para></listitem> + + <listitem><para>Metadata on files in the Nix store is canonicalised + after builds: the last-modified timestamp is set to 0 (00:00:00 + 1/1/1970), the mode is set to 0444 or 0555 (readable and possibly + executable by all; setuid/setgid bits are dropped), and the group is + set to the default. This ensures that the result of a build and an + installation through a substitute is the same; and that timestamp + dependencies are revealed.</para></listitem> + +</itemizedlist> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.6 (November 14, 2004)</title> + +<itemizedlist> + + <listitem> + <para>Rewrite of the normalisation engine. + + <itemizedlist> + + <listitem><para>Multiple builds can now be performed in parallel + (option <option>-j</option>).</para></listitem> + + <listitem><para>Distributed builds. Nix can now call a shell + script to forward builds to Nix installations on remote + machines, which may or may not be of the same platform + type.</para></listitem> + + <listitem><para>Option <option>--fallback</option> allows + recovery from broken substitutes.</para></listitem> + + <listitem><para>Option <option>--keep-going</option> causes + building of other (unaffected) derivations to continue if one + failed.</para></listitem> + + </itemizedlist> + + </para> + + </listitem> + + <listitem><para>Improvements to the garbage collector (i.e., it + should actually work now).</para></listitem> + + <listitem><para>Setuid Nix installations allow a Nix store to be + shared among multiple users.</para></listitem> + + <listitem><para>Substitute registration is much faster + now.</para></listitem> + + <listitem><para>A utility <command>nix-build</command> to build a + Nix expression and create a symlink to the result int the current + directory; useful for testing Nix derivations.</para></listitem> + + <listitem><para>Manual updates.</para></listitem> + + <listitem> + + <para><command>nix-env</command> changes: + + <itemizedlist> + + <listitem><para>Derivations for other platforms are filtered out + (which can be overridden using + <option>--system-filter</option>).</para></listitem> + + <listitem><para><option>--install</option> by default now + uninstall previous derivations with the same + name.</para></listitem> + + <listitem><para><option>--upgrade</option> allows upgrading to a + specific version.</para></listitem> + + <listitem><para>New operation + <option>--delete-generations</option> to remove profile + generations (necessary for effective garbage + collection).</para></listitem> + + <listitem><para>Nicer output (sorted, + columnised).</para></listitem> + + </itemizedlist> + + </para> + + </listitem> + + <listitem><para>More sensible verbosity levels all around (builder + output is now shown always, unless <option>-Q</option> is + given).</para></listitem> + + <listitem> + + <para>Nix expression language changes: + + <itemizedlist> + + <listitem><para>New language construct: <literal>with + <replaceable>E1</replaceable>; + <replaceable>E2</replaceable></literal> brings all attributes + defined in the attribute set <replaceable>E1</replaceable> in + scope in <replaceable>E2</replaceable>.</para></listitem> + + <listitem><para>Added a <function>map</function> + function.</para></listitem> + + <listitem><para>Various new operators (e.g., string + concatenation).</para></listitem> + + </itemizedlist> + + </para> + + </listitem> + + <listitem><para>Expression evaluation is much + faster.</para></listitem> + + <listitem><para>An Emacs mode for editing Nix expressions (with + syntax highlighting and indentation) has been + added.</para></listitem> + + <listitem><para>Many bug fixes.</para></listitem> + +</itemizedlist> + +</section> + + + +<!--==================================================================--> + +<section><title>Release 0.5 and earlier</title> + +<para>Please refer to the Subversion commit log messages.</para> + +</section> + + + +</article> |