<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
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version="5.0"
xml:id="ssec-relnotes-1.12">
<title>Release 1.12 (TBA)</title>
<para>This release has the following new features:</para>
<itemizedlist>
<listitem>
<para>Start of new <command>nix</command> command line
interface. This is a work in progress and the interface is subject
to change.</para>
<itemizedlist>
<listitem><para>Self-documenting: <option>--help</option> shows
all available command-line arguments.</para></listitem>
<listitem><para><option>--help-config</option> shows all
configuration options.</para></listitem>
<listitem><para><command>nix build</command>: Replacement for
<command>nix-build</command>.</para></listitem>
<listitem><para><command>nix ls-store</command> and <command>nix
ls-nar</command> allow listing the contents of a store path or
NAR file.</para></listitem>
<listitem><para><command>nix cat-store</command> and
<command>nix cat-nar</command> allow extracting a file from a
store path or NAR file.</para></listitem>
<listitem><para><command>nix verify</command> checks whether a
store path is unmodified and/or is trusted.</para></listitem>
<listitem><para><command>nix copy-sigs</command> copies
signatures from one store to another.</para></listitem>
<listitem><para><command>nix sign-paths</command> signs store
paths.</para></listitem>
<listitem><para><command>nix copy</command> copies paths between
arbitrary Nix stores, generalising
<command>nix-copy-closure</command> and
<command>nix-push</command>.</para></listitem>
<listitem><para><command>nix path-info</command> shows
information about store paths.</para></listitem>
<listitem><para><command>nix run</command> starts a shell in
which the specified packages are available. (TODO: currently
broken in chroot mode)</para></listitem>
<listitem><para><command>nix log</command> shows the build log
of a package or path. If the build log is not available locally,
it will try to obtain it from a binary cache.</para></listitem>
<listitem><para><command>nix eval</command> replaces
<command>nix-instantiate --eval</command>.</para></listitem>
<listitem><para><command>nix dump-path</command> to get a NAR
from a store path.</para></listitem>
<listitem><para><command>nix edit</command> opens the source
code of a package in an editor.</para></listitem>
<listitem><para><command>nix search</command> replaces
<command>nix-env -qa</command>. It searches the available
packages for occurences of a search string in the attribute
name, package name or description. It caches available packages
to speed up searches.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>The external program <command>nix-repl</command> has been
integrated into Nix as <command>nix repl</command>.</para>
</listitem>
<listitem>
<para>Nix now supports floating-point numbers.</para>
</listitem>
<listitem>
<para>New build mode <command>nix-build --hash</command> that
builds a derivation, computes the hash of the output, and moves
the output to the store path corresponding to what a fixed-output
derivation with that hash would produce.
(Add docs and examples; see d367b8e7875161e655deaa96bf8a5dd0bcf8229e)</para>
</listitem>
<listitem>
<para>It is no longer necessary to set the
<envar>NIX_REMOTE</envar> environment variable if you need to use
the Nix daemon. Nix will use the daemon automatically if you don’t
have write access to the Nix database.</para>
</listitem>
<listitem>
<para>The Nix language now supports floating point numbers. They are
based on regular C++ <literal>float</literal> and compatible with
existing integers and number-related operations. Export and import to and
from JSON and XML works, too.</para>
</listitem>
<listitem>
<para><command>nix-shell</command> now sets the
<varname>IN_NIX_SHELL</varname> environment variable during
evaluation and in the shell itself. This can be used to perform
different actions depending on whether you’re in a Nix shell or in
a regular build. Nixpkgs provides
<varname>lib.inNixShell</varname> to check this variable during
evaluation. (bb36a1a3cf3fbe6bc9d0afcc5fa0f928bed03170)</para>
</listitem>
<listitem>
<para>Internal: all <classname>Store</classname> classes are now
thread-safe. <classname>RemoteStore</classname> supports multiple
concurrent connections to the daemon. This is primarily useful in
multi-threaded programs such as
<command>hydra-queue-runner</command>.</para>
</listitem>
<listitem>
<para>The dependency on Perl has been removed. As a result, some
(obsolete) programs have been removed: <command>nix-push</command>
(replaced by <command>nix copy</command>),
<command>nix-pull</command> (obsoleted by binary caches),
<command>nix-generate-patches</command>,
<command>bsdiff</command>, <command>bspatch</command>.</para>
</listitem>
<listitem>
<para>Improved store abstraction. Substituters
eliminated. BinaryCacheStore, LocalBinaryCacheStore,
HttpBinaryCacheStore, S3BinaryCacheStore (compile-time
optional), SSHStore. Add docs + examples?
</para>
</listitem>
<listitem>
<para>Nix now stores signatures for local store
paths. Locally-built paths are now signed automatically using the
secret keys specified by the <option>secret-key-files</option>
store option.</para>
<para>In addition, store paths that have been built locally are
marked as “ultimately trusted”, and content-addressable store
paths carry a “content-addressability assertion” that allow them
to be trusted without any signatures.</para>
</listitem>
<listitem>
<para><envar>NIX_PATH</envar> is now lazy, so URIs in the path are
only downloaded if they are needed for evaluation.</para>
</listitem>
<listitem>
<para>You can now use
<uri>channel:<replaceable>channel-name</replaceable></uri> as a
short-hand for
<uri>https://nixos.org/channels/<replaceable>channel-name</replaceable>/nixexprs.tar.xz</uri>. For
example, <literal>nix-build channel:nixos-15.09 -A hello</literal>
will build the GNU Hello package from the
<literal>nixos-15.09</literal> channel.</para>
</listitem>
<listitem>
<para>“Nested” log output was removed. As a result,
<command>nix-log2xml</command> was also removed.</para>
</listitem>
<listitem>
<para>When <option>--no-build-output</option> is given, the last
10 lines of the build log will be shown if a build
fails.</para>
</listitem>
<listitem>
<para><function>builtins.fetchgit</function>.
(38539b943a060d9cdfc24d6e5d997c0885b8aa2f)</para>
</listitem>
<listitem>
<para>Git repositories can now be specified in the Nix search
path,
e.g. <literal>nixpkgs=git://github.com/NixOS/nixpkgs</literal>.
(d8bf0d4859e28ddd23401fbe89f4e528aa09ddb3)</para>
</listitem>
<listitem>
<para>Removed OpenSSL-based signing. (f435f8247553656774dd1b2c88e9de5d59cab203)</para>
</listitem>
<listitem>
<para><literal><nix/fetchurl.nix></literal> now uses the
content-addressable tarball cache at
<uri>http://tarballs.nixos.org/</uri>, just like
<function>fetchurl</function> in
Nixpkgs. (f2682e6e18a76ecbfb8a12c17e3a0ca15c084197)</para>
</listitem>
<listitem>
<para>Chroot Nix stores: allow the “physical” location of the Nix
store (e.g. <filename>/home/alice/nix/store</filename>) to differ
from its “logical” location (typically
<filename>/nix/store</filename>). This allows non-root users to
use Nix while still getting the benefits from prebuilt binaries
from
<uri>cache.nixos.org</uri>. (4494000e04122f24558e1436e66d20d89028b4bd,
3eb621750848e0e6b30e5a79f76afbb096bb6c8a)</para>
</listitem>
<listitem>
<para>On Linux, builds are now executed in a user
namespace with uid 1000 and gid 100.</para>
</listitem>
<listitem>
<para><function>builtins.fetchurl</function> and
<function>builtins.fetchTarball</function> now support
<varname>sha256</varname> and <varname>name</varname>
attributes. Using these functions is now allowed in restricted
mode if a hash is supplied.</para>
</listitem>
<listitem>
<para><literal>HttpBinaryCacheStore</literal> (the replacement of
<command>download-from-binary-cache</command>) now retries
automatically on certain HTTP error codes.</para>
</listitem>
<listitem>
<para>Derivation attributes can now reference the outputs of the
derivation using the <function>placeholder</function> builtin
function. For example, the attribute
<programlisting>
configureFlags = "--prefix=${placeholder "out"} --includedir=${placeholder "dev"}";
</programlisting>
will cause the <envar>configureFlags</envar> environment variable
to contain the actual store paths corresponding to the
<literal>out</literal> and <literal>dev</literal> outputs. TODO:
add docs.</para>
</listitem>
<listitem>
<para>Added builtin function
<varname>builtins.partition</varname>.</para>
</listitem>
<listitem>
<para>Support for HTTP/2. This makes binary cache lookups much
more efficient. (90ad02bf626b885a5dd8967894e2eafc953bdf92)</para>
</listitem>
<listitem>
<para>Caching of failed builds has been
removed. (8cffec84859cec8b610a2a22ab0c4d462a9351ff)</para>
</listitem>
<listitem>
<para>The <option>build-sandbox-paths</option> configuration
option can now specify optional paths by appending a
<literal>?</literal>, e.g. <literal>/dev/nvidiactl?</literal> will
bind-mount <varname>/dev/nvidiactl</varname> only if it
exists.</para>
</listitem>
<listitem>
<para>More support for testing build reproducibility: when
<option>enforce-determinism</option> is set to
<literal>false</literal>, it’s no longer a fatal error build
rounds produce different output
(8bdf83f936adae6f2c907a6d2541e80d4120f051); add a hook to run
diffoscope when build rounds produce different output
(9a313469a4bdea2d1e8df24d16289dc2a172a169w).</para>
</listitem>
<listitem>
<para>Kill builds as soon as stdout/stderr is closed. This fixes a
bug that allowed builds to hang Nix indefinitely (regardless of
timeouts). (21948deed99a3295e4d5666e027a6ca42dc00b40)</para>
</listitem>
<listitem>
<para>Add support for passing structured data to builders. TODO:
document. (6de33a9c675b187437a2e1abbcb290981a89ecb1)</para>
</listitem>
<listitem>
<para><varname>exportReferencesGraph</varname>: Export more
complete info in JSON
format. (c2b0d8749f7e77afc1c4b3e8dd36b7ee9720af4a)</para>
</listitem>
<listitem>
<para>Support for
netrc. (e6e74f987f0fa284d220432d426eb965269a97d6,
302386f775eea309679654e5ea7c972fb6e7b9af)</para>
</listitem>
<listitem>
<para>Support <uri>s3://</uri> URIs in all places where Nix allows
URIs. (9ff9c3f2f80ba4108e9c945bbfda2c64735f987b)</para>
</listitem>
<listitem>
<para>The <option>build-max-jobs</option> option can be set to
<literal>auto</literal> to use the number of CPUs in the
system. (7251d048fa812d2551b7003bc9f13a8f5d4c95a5)</para>
</listitem>
<listitem>
<para>Add support for Brotli compression.
<uri>cache.nixos.org</uri> compresses build logs using
Brotli.</para>
</listitem>
<listitem>
<para>Substitutions from binary caches now require signatures by
default. This was already the case on
NixOS. (ecbc3fedd3d5bdc5a0e1a0a51b29062f2874ac8b)</para>
</listitem>
<listitem>
<para><command>nix-env</command> now ignores packages with bad
derivation names (in particular those starting with a digit or
containing a
dot). (b0cb11722626e906a73f10dd9a0c9eea29faf43a)</para>
</listitem>
<listitem>
<para>Renamed various configuration options. (TODO: in progress)</para>
</listitem>
<listitem>
<para>Remote machines can now be specified on the command
line. TODO:
document. (1a68710d4dff609bbaf61db3e17a2573f0aadf17)</para>
</listitem>
<listitem>
<para>In Linux sandbox builds, we now use
<filename>/build</filename> instead of <filename>/tmp</filename>
as the temporary build directory. This fixes potential security
problems when a build accidentally stores its
<envar>TMPDIR</envar> in some critical place, such as an
RPATH. (eba840c8a13b465ace90172ff76a0db2899ab11b)</para>
</listitem>
<listitem>
<para>In Linux sandbox builds, we now provide a default
<filename>/bin/sh</filename> (namely <filename>ash</filename> from
BusyBox). (a2d92bb20e82a0957067ede60e91fab256948b41)</para>
</listitem>
<listitem>
<para>Make all configuration options available as command line
flags (b8283773bd64d7da6859ed520ee19867742a03ba).</para>
</listitem>
<listitem>
<para>Support base-64
hashes. (c0015e87af70f539f24d2aa2bc224a9d8b84276b)</para>
</listitem>
<listitem>
<para><command>nix-shell</command> now used
<varname>bashInteractive</varname> from Nixpkgs, rather than the
<command>bash</command> command that happens to be in the caller’s
<envar>PATH</envar>. This is especially important on macOS where
the <command>bash</command> provided by the system is seriously
outdated and cannot execute <literal>stdenv</literal>’s setup
script.</para>
</listitem>
<listitem>
<para><function>builtins.split</function>.
(b8867a0239b1930a16f9ef3f7f3e864b01416dff))</para>
</listitem>
<listitem>
<para><filename>nix-mode.el</filename> has been removed from Nix. It is now a separate repository
in <uri>https://github.com/NixOS/nix-mode</uri> and can be installed through the MELPA
package repository.</para>
</listitem>
<listitem>
<para>Automatic garbage collection.</para>
</listitem>
<listitem>
<para><command>nix why-depends</command></para>
</listitem>
<listitem>
<para><command>nix-store -q --roots</command> and
<command>nix-store --gc --print-roots</command> now show temporary
and in-memory roots.</para>
</listitem>
</itemizedlist>
<para>This release has contributions from TBD.</para>
</section>