gomi: embed version information (#403076)

pkgs/by-name/go/gomi/package.nix

@@ -12,13 +12,32 @@ buildGoModule rec {
     owner = "b4b4r07";
     repo = "gomi";
     tag = "v${version}";
-    hash = "sha256-FZCvUG6lQH8CFivV/hbIgGQx4FCk1UtreiWXTQVi4+4=";
+    hash = "sha256-0C+us4GO8Jd51ATaaf0aRU3NnhmDvu0I3qDDXBoaiXU=";
+    # populate values that require us to use git. By doing this in postFetch we
+    # can delete .git afterwards and maintain better reproducibility of the src.
+    leaveDotGit = true;
+    postFetch = ''
+      cd $out
+      git show --format='%h' HEAD --quiet > ldflags_revision
+      date --utc --date="@$(git show --format='%ct' HEAD --quiet)" +'%Y-%m-%dT%H:%M:%SZ' > ldflags_buildDate
+      find . -type d -name .git -print0 | xargs -0 rm -rf
+    '';
   };
 
   vendorHash = "sha256-8aw81DKBmgNsQzgtHCsUkok5e5+LeAC8BUijwKVT/0s=";
 
   subPackages = [ "." ];
 
+  # Add version information fetched from the repository to ldflags.
+  # https://github.com/babarot/gomi/blob/v1.6.0/.goreleaser.yaml#L20-L22
+  ldflags = [
+    "-X main.version=v${version}"
+  ];
+  preBuild = ''
+    ldflags+=" -X main.revision=$(cat ldflags_revision)"
+    ldflags+=" -X main.buildDate=$(cat ldflags_buildDate)"
+  '';
+
   meta = {
     description = "Replacement for UNIX rm command";
     homepage = "https://github.com/b4b4r07/gomi";