diff options
Diffstat (limited to 'doc/manual/expressions/advanced-attributes.xml')
| -rw-r--r-- | doc/manual/expressions/advanced-attributes.xml | 54 |
1 files changed, 27 insertions, 27 deletions
diff --git a/doc/manual/expressions/advanced-attributes.xml b/doc/manual/expressions/advanced-attributes.xml index d476d613e462..274e36f5c1d0 100644 --- a/doc/manual/expressions/advanced-attributes.xml +++ b/doc/manual/expressions/advanced-attributes.xml @@ -90,6 +90,33 @@ derivation { </varlistentry> + <varlistentry><term><varname>impureEnvVars</varname></term> + + <listitem><para>This attribute allows you to specify a list of + environment variables that should be passed from the environment + of the calling user to the builder. Usually, the environment is + cleared completely when the builder is executed, but with this + attribute you can allow specific environment variables to be + passed unmodified. For example, <function>fetchurl</function> in + Nixpkgs has the line + +<programlisting> +impureEnvVars = [ "http_proxy" "https_proxy" <replaceable>...</replaceable> ]; +</programlisting> + + to make it use the proxy server configuration specified by the + user in the environment variables <envar>http_proxy</envar> and + friends.</para> + + <para>This attribute is only allowed in <link + linkend="fixed-output-drvs">fixed-output derivations</link>, where + impurities such as these are okay since (the hash of) the output + is known in advance. It is ignored for all other + derivations.</para></listitem> + + </varlistentry> + + <varlistentry xml:id="fixed-output-drvs"> <term><varname>outputHash</varname></term> <term><varname>outputHashAlgo</varname></term> @@ -215,33 +242,6 @@ stdenv.mkDerivation { </varlistentry> - <varlistentry><term><varname>impureEnvVars</varname></term> - - <listitem><para>This attribute allows you to specify a list of - environment variables that should be passed from the environment - of the calling user to the builder. Usually, the environment is - cleared completely when the builder is executed, but with this - attribute you can allow specific environment variables to be - passed unmodified. For example, <function>fetchurl</function> in - Nixpkgs has the line - -<programlisting> -impureEnvVars = [ "http_proxy" "https_proxy" <replaceable>...</replaceable> ]; -</programlisting> - - to make it use the proxy server configuration specified by the - user in the environment variables <envar>http_proxy</envar> and - friends.</para> - - <para>This attribute is only allowed in <link - linkend="fixed-output-drvs">fixed-output derivations</link>, where - impurities such as these are okay since (the hash of) the output - is known in advance. It is ignored for all other - derivations.</para></listitem> - - </varlistentry> - - <varlistentry><term><varname>preferLocalBuild</varname></term> <listitem><para>If this attribute is set to |