This commit is contained in:
Eelco Dolstra 2007-10-22 12:46:15 +00:00
parent f90d85107e
commit 1db187ff69
1 changed files with 14 additions and 15 deletions

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@ -1,4 +1,4 @@
chapter xmlns="http://docbook.org/ns/docbook"
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id='chap-writing-nix-expressions'>
@ -526,16 +526,15 @@ genericBuild <co xml:id='ex-hello-builder2-co-3' /></programlisting>
<filename>bin</filename> subdirectory, it's added to
<envar>PATH</envar>; if it has a <filename>include</filename>
subdirectory, it's added to GCC's header search path; and so
on.
<footnote><para>How does it work? setup tries sourcing
$out/nix-support/setup-hook of all dependencies
thereby defining environment variables.
If you have A depending on B depending on C
you can force the setup-hooks of C beeing sourced when evaluating
expression A by using
<programlisting>propagatedBuildInputs=[ C ];</programlisting>
instead of buildInputs when defining derivation B.
</para></footnote></para>
on.<footnote><para>How does it work? <filename>setup</filename>
tries to source the file
<filename><replaceable>pkg</replaceable>/nix-support/setup-hook</filename>
of all dependencies. These “setup hooks” can then set up whatever
environment variables they want; for instance, the setup hook for
Perl sets the <envar>PERL5LIB</envar> environment variable to
contain the <filename>lib/site_perl</filename> directories of all
inputs.</para></footnote>
</para>
</callout>
@ -544,7 +543,7 @@ genericBuild <co xml:id='ex-hello-builder2-co-3' /></programlisting>
<para>The function <function>genericBuild</function> is defined in
the file <literal>$stdenv/setup</literal>.</para>
</callout> looks for a file nix-support/setup-hook within the derivation path.
</callout>
<callout arearefs='ex-hello-builder2-co-3'>
@ -1226,9 +1225,9 @@ set, the attributes of which specify the inputs of the build.</para>
They are simply concatenated, separated by
spaces.</para></listitem>
<listitem><para><emphasis>true</emphasis> is passed as
<emphasis>1</emphasis>, <emphasis>false</emphasis>
and <emphasis>null</emphasis> are passed as empty string.
<listitem><para><literal>true</literal> is passed as the string
<literal>1</literal>, <literal>false</literal> and
<literal>null</literal> are passed as an empty string.
</para></listitem>
</itemizedlist>