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diff --git a/doc/manual/release-notes/rl-0.11.xml b/doc/manual/release-notes/rl-0.11.xml new file mode 100644 index 000000000..40f83bbc7 --- /dev/null +++ b/doc/manual/release-notes/rl-0.11.xml @@ -0,0 +1,261 @@ +<chapter 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="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> + +</chapter>
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