diff options
Diffstat (limited to 'doc/manual/builtins.xml')
| -rw-r--r-- | doc/manual/builtins.xml | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/doc/manual/builtins.xml b/doc/manual/builtins.xml index 1f881a91177a..3eee36f2aec7 100644 --- a/doc/manual/builtins.xml +++ b/doc/manual/builtins.xml @@ -77,18 +77,8 @@ attrValues = attrs: map (name: builtins.getAttr name attrs) (builtins.attrNames if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> This allows a Nix expression to fall back gracefully on older Nix - installations that don’t have the desired built-in function. - However, in that case you should not write - -<programlisting> -if builtins ? getEnv then __getEnv "PATH" else ""</programlisting> - - This Nix expression will trigger an “undefined variable” error on - older Nix versions since <function>__getEnv</function> doesn’t - exist. <literal>builtins.getEnv</literal>, on the other hand, is - safe since <literal>builtins</literal> always exists and attribute - selection is lazy, so it’s only performed if the test - succeeds.</para></listitem> + installations that don’t have the desired built-in + function.</para></listitem> </varlistentry> |