path: root/doc/manual/expressions/standard-env.xml

<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='sec-standard-environment'>

<title>The Standard Environment</title>


<para>The standard environment is used by passing it as an input
called <envar>stdenv</envar> to the derivation, and then doing

<programlisting>
source $stdenv/setup</programlisting>

at the top of the builder.</para>

<para>Apart from adding the aforementioned commands to the
<envar>PATH</envar>, <filename>setup</filename> also does the
following:

<itemizedlist>

  <listitem><para>All input packages specified in the
  <envar>buildInputs</envar> environment variable have their
  <filename>/bin</filename> subdirectory added to <envar>PATH</envar>,
  their <filename>/include</filename> subdirectory added to the C/C++
  header file search path, and their <filename>/lib</filename>
  subdirectory added to the linker search path.  This can be extended.
  For instance, when the <command>pkgconfig</command> package is
  used, the subdirectory <filename>/lib/pkgconfig</filename> of each
  input is added to the <envar>PKG_CONFIG_PATH</envar> environment
  variable.</para></listitem>

  <listitem><para>The environment variable
  <envar>NIX_CFLAGS_STRIP</envar> is set so that the compiler strips
  debug information from object files.  This can be disabled by
  setting <envar>NIX_STRIP_DEBUG</envar> to
  <literal>0</literal>.</para></listitem>

</itemizedlist>

</para>

<para>The <filename>setup</filename> script also exports a function
called <function>genericBuild</function> that knows how to build
typical Autoconf-style packages.  It can be customised to perform
builds for any type of package.  It is advisable to use
<function>genericBuild</function> since it provides facilities that
are almost always useful such as unpacking of sources, patching of
sources, nested logging, etc.</para>

<para>The definitive, up-to-date documentation of the generic builder
is the source itself, which resides in
<filename>pkgs/stdenv/generic/setup.sh</filename>.</para>

<xi:include href="custom-builder.xml" />
<xi:include href="debug-build.xml" />

</chapter>