Merge pull request #1066 from antoineco/zsh/fpath

Backport Zsh fpath mangling from NixOS

modules/programs/zsh/default.nix

@@ -135,6 +135,11 @@ in
         . ${config.system.build.setEnvironment}
       fi
 
+      # Tell zsh how to find installed completions
+      for p in ''${(z)NIX_PROFILES}; do
+        fpath=($p/share/zsh/site-functions $p/share/zsh/$ZSH_VERSION/functions $p/share/zsh/vendor-completions $fpath)
+      done
+
       ${cfg.shellInit}
 
       # Read system-wide modifications.
@@ -182,11 +187,6 @@ in
       ${config.environment.interactiveShellInit}
       ${cfg.interactiveShellInit}
 
-      # Tell zsh how to find installed completions
-      for p in ''${(z)NIX_PROFILES}; do
-        fpath+=($p/share/zsh/site-functions $p/share/zsh/$ZSH_VERSION/functions $p/share/zsh/vendor-completions)
-      done
-
       ${cfg.promptInit}
 
       ${optionalString cfg.enableGlobalCompInit "autoload -U compinit && compinit"}