1 files changed, 48 insertions, 0 deletions
diff --git a/pkgs/misc/merge.nix b/pkgs/misc/merge.nix
new file mode 100644
index 0000000..9d6eabb
--- /dev/null
+++ b/pkgs/misc/merge.nix
@@ -0,0 +1,48 @@
+{ runCommand, writeShellApplication, rsync, lib, ... }:
+args@{ name, paths, preferLocalBuild ? true, allowSubstitutes ? false, postBuild ? "" }:
+let
+  env = builtins.removeAttrs args [ "name" "postBuild" ]] // {
+    inherit preferLocalBuild allowSubstitutes;
+    nativeBuildInputs = (args.nativeBuildInputs or []) ++ [
+      rsync
+      replaceBadSymlink
+    ];
+    passAsFile = [ "paths" ];
+  };
+
+  # copyDirs = p: ''
+  #   ${lib.getExe rsync} -rv --copy-dirlinks --links --executability "${p}/" "$out"
+  # '';
+
+  replaceBadSymlink = writeShellApplication {
+    name = "replaceBadSymlink";
+    # runtimeInputs = [ coreutils ];
+    text = ''
+      FILE="''${1-}"
+
+      if [[ -z "$FILE" ]]; then
+        >&2 echo "Need a file input"
+      fi
+
+      REALPATH="$(readlink -f "$FILE")"
+
+      case "$REALPATH" in
+        "/nix/store/"* )
+          echo "Replacing $FILE by $REALPATH"
+          cp -v --remove-destination "$REALPATH" "$FILE"
+        ;;
+      esac
+    '';
+  };
+
+in runCommand name env ''
+  mkdir -p $out
+
+  for i in $(cat $pathsPath); do
+    rsync -rv --copy-dirlinks --links --executability "$i/" "$out"
+  done
+
+  find $out -type l -exec "replaceBadSymlink {}" \;
+
+  ${postBuild}
+''