Use lib.pathIsGitRepo

Shay Bergmann · Shay Bergmann · commit 642b869364b2 · 2020-09-29T05:34:16.000-04:00
instead of just checking for the existence of `.git`. It covers more
cases that way.
diff --git a/nix/pkgs/mantis/default.nix b/nix/pkgs/mantis/default.nix
@@ -2,7 +2,7 @@
 
   mkSrc = src:
     let
-      isGit = builtins.pathExists (src + "/.git");
+      isGit = lib.pathIsGitRepo src;
       repo = builtins.fetchGit { url = src; submodules = true; };
       dirty = repo.revCount == 0;
       filterSrc = src:
