nixpkgs/doc/contributing/contributing-to-documentation.xml

<chapter xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xml:id="chap-contributing">
 <title>Contributing to this documentation</title>
 <para>
  The DocBook sources of the Nixpkgs manual are in the <filename
xlink:href="https://github.com/NixOS/nixpkgs/tree/master/doc">doc</filename> subdirectory of the Nixpkgs repository.
 </para>
 <para>
  You can quickly check your edits with <command>make</command>:
 </para>
<screen>
<prompt>$ </prompt>cd /path/to/nixpkgs/doc
<prompt>$ </prompt>nix-shell
<prompt>[nix-shell]$ </prompt>make
</screen>
 <para>
  If you experience problems, run <command>make debug</command> to help understand the docbook errors.
 </para>
 <para>
  After making modifications to the manual, it's important to build it before committing. You can do that as follows:
<screen>
<prompt>$ </prompt>cd /path/to/nixpkgs/doc
<prompt>$ </prompt>nix-shell
<prompt>[nix-shell]$ </prompt>make clean
<prompt>[nix-shell]$ </prompt>nix-build .
</screen>
  If the build succeeds, the manual will be in <filename>./result/share/doc/nixpkgs/manual.html</filename>.
 </para>
</chapter>