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Diffstat (limited to 'third_party/nix/doc/manual/release-notes/rl-0.8.xml')
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diff --git a/third_party/nix/doc/manual/release-notes/rl-0.8.xml b/third_party/nix/doc/manual/release-notes/rl-0.8.xml new file mode 100644 index 000000000000..784b26c6b7d3 --- /dev/null +++ b/third_party/nix/doc/manual/release-notes/rl-0.8.xml @@ -0,0 +1,246 @@ +<section xmlns="http://docbook.org/ns/docbook" + xmlns:xlink="http://www.w3.org/1999/xlink" + xmlns:xi="http://www.w3.org/2001/XInclude" + version="5.0" + xml:id="ch-relnotes-0.8"> + +<title>Release 0.8 (2005-04-11)</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> |