diff --git a/packaging/components.nix b/packaging/components.nix
index b1ef38302f5..8b027591e6e 100644
--- a/packaging/components.nix
+++ b/packaging/components.nix
@@ -102,7 +102,7 @@ let
         let
           n = lib.length finalScope.patches;
         in
-        if n == 0 then finalAttrs.version else finalAttrs.version + "+${toString n}";
+        if n == 0 then prevAttrs.version else prevAttrs.version + "+${toString n}";
 
       # Clear what `derivation` can't/shouldn't serialize; see prevAttrs.workDir.
       fileset = null;
@@ -256,7 +256,10 @@ in
                 inherit (finalScope) src patches;
               }
             );
+
         resolvePath = p: finalScope.patchedSrc + "/${resolveRelPath p}";
+        filesetToSource = { root, fileset }: finalScope.resolvePath root;
+
         appendPatches = appendPatches finalScope;
       }
     );
diff --git a/src/libstore-tests/package.nix b/src/libstore-tests/package.nix
index b39ee7fa73c..cdaa04fbe76 100644
--- a/src/libstore-tests/package.nix
+++ b/src/libstore-tests/package.nix
@@ -17,6 +17,7 @@
 
   version,
   filesetToSource,
+  resolvePath,
 }:
 
 let
@@ -79,7 +80,7 @@ mkMesonExecutable (finalAttrs: {
               mkdir -p "$HOME"
             ''
             + ''
-              export _NIX_TEST_UNIT_DATA=${data + "/src/libstore-tests/data"}
+              export _NIX_TEST_UNIT_DATA=${resolvePath ./data/src/libstore-tests/data}
               ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
               touch $out
             ''
diff --git a/src/libutil-tests/package.nix b/src/libutil-tests/package.nix
index c06de6894af..b8d54b76c42 100644
--- a/src/libutil-tests/package.nix
+++ b/src/libutil-tests/package.nix
@@ -15,6 +15,7 @@
   # Configuration Options
 
   version,
+  resolvePath,
 }:
 
 let
@@ -61,7 +62,7 @@ mkMesonExecutable (finalAttrs: {
               mkdir -p "$HOME"
             ''
             + ''
-              export _NIX_TEST_UNIT_DATA=${./data}
+              export _NIX_TEST_UNIT_DATA=${resolvePath ./data}
               ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
               touch $out
             ''