Only use source fixed output path if SHA256 algorithm

Author: puffnfresh

hnix-store-core/src/System/Nix/ReadonlyStore.hs

@@ -28,12 +28,12 @@ makeTextPath nm h refs = makeStorePath ty h nm
   where
     ty = BS.intercalate ":" ("text" : map storePathToRawFilePath (HS.toList refs))
 
-makeFixedOutputPath :: (KnownStoreDir storeDir, ValidAlgo hashAlgo, NamedAlgo hashAlgo) => Bool -> Digest hashAlgo -> StorePathName -> StorePath storeDir
+makeFixedOutputPath :: forall storeDir hashAlgo. (KnownStoreDir storeDir, ValidAlgo hashAlgo, NamedAlgo hashAlgo) => Bool -> Digest hashAlgo -> StorePathName -> StorePath storeDir
 makeFixedOutputPath recursive h nm =
   makeStorePath ty h' nm
   where
     (ty, h') =
-      if recursive
+      if recursive && algoName @hashAlgo == algoName @'SHA256
       then ("source", h)
       else ("output:out", hash ("fixed:out:" <> encodeUtf8 (encodeBase16 h) <> ":"))