doc/builders/trivial-builders: added runCommandLocal docs

The link in the note points to the `id` added in
https://github.com/NixOS/nix/pull/3255, so it might take some time to
start working correctly.
This commit is contained in:
Profpatsch 2019-11-29 16:59:08 +01:00
parent 8deaf41d60
commit faa3e54fe0

View file

@ -50,6 +50,19 @@
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>runCommandLocal</literal>, <literal>runCommandCCLocal</literal>
</term>
<listitem>
<para>
Variants of <literal>runCommand</literal> and <literal>runCommandCC</literal> that force the derivation to be built locally, it is not substituted. This is intended for very cheap commands (&lt;1s execution time). It saves on the network roundrip and can speed up a build.
</para>
<note><para>
This sets <link xlink:href="https://nixos.org/nix/manual/#adv-attr-allowSubstitutes"><literal>allowSubstitutes</literal> to <literal>false</literal></link>, so only use <literal>runCommandLocal</literal> if you are certain the user will always have a builder for the <literal>system</literal> of the derivation. This should be true for most trivial use cases (e.g. just copying some files to a different location or adding symlinks), because there the <literal>system</literal> is usually the same as <literal>builtins.currentSystem</literal>.
</para></note>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>writeTextFile</literal>, <literal>writeText</literal>, <literal>writeTextDir</literal>, <literal>writeScript</literal>, <literal>writeScriptBin</literal>