diff --git a/src/Outpaths.hs b/src/Outpaths.hs
index 6b4f190..ec40ff5 100644
--- a/src/Outpaths.hs
+++ b/src/Outpaths.hs
@@ -31,13 +31,13 @@ let
   lib = import (path + "/lib");
   hydraJobs = import (path + "/pkgs/top-level/release.nix")
     # Compromise: accuracy vs. resources needed for evaluation.
+    # we only evaluate one architecture per OS as we most likely catch all
+    # mass-rebuilds this way.
     {
       supportedSystems = [
-        "aarch64-linux"
-        "i686-linux"
         "x86_64-linux"
         "x86_64-darwin"
-      ];
+     ];
 
       nixpkgsArgs = {
         config = {
diff --git a/src/Skiplist.hs b/src/Skiplist.hs
index c64bcc5..f496cbf 100644
--- a/src/Skiplist.hs
+++ b/src/Skiplist.hs
@@ -135,7 +135,8 @@ contentList =
     infixOf "buildPerlPackage" "Derivation contains buildPerlPackage",
     -- Specific skips for classes of packages
     infixOf "goDeps" "Derivation contains goDeps attribute",
-    infixOf "https://downloads.haskell.org/ghc/" "GHC packages are versioned per file"
+    infixOf "https://downloads.haskell.org/ghc/" "GHC packages are versioned per file",
+    infixOf "gnome" "Do not update GNOME during a release cycle"
   ]
 
 checkResultList :: Skiplist
diff --git a/src/Update.hs b/src/Update.hs
index 1aa7495..cc60e9c 100644
--- a/src/Update.hs
+++ b/src/Update.hs
@@ -303,8 +303,9 @@ updateAttrPath log updateEnv@UpdateEnv {..} mergeBaseOutpathsContext attrPath =
 
     -- Get the original values for diffing purposes
     derivationContents <- liftIO $ T.readFile derivationFile
-    oldHash <- Nix.getOldHash attrPath
-    oldSrcUrl <- Nix.getSrcUrl attrPath
+    oldHash <- Nix.getOldHash attrPath <|> pure ""
+    oldSrcUrl <- Nix.getSrcUrl attrPath <|> pure ""
+    oldRev <- Nix.getAttr Nix.Raw "rev" attrPath <|> pure ""
     oldVerMay <- rightMay `fmapRT` (lift $ runExceptT $ Nix.getAttr Nix.Raw "version" attrPath)
 
     tryAssert
@@ -330,8 +331,9 @@ updateAttrPath log updateEnv@UpdateEnv {..} mergeBaseOutpathsContext attrPath =
       (diffAfterRewrites /= T.empty)
     lift . log $ "Diff after rewrites:\n" <> diffAfterRewrites
     updatedDerivationContents <- liftIO $ T.readFile derivationFile
-    newSrcUrl <- Nix.getSrcUrl attrPath
-    newHash <- Nix.getHash attrPath
+    newSrcUrl <- Nix.getSrcUrl attrPath <|> pure ""
+    newHash <- Nix.getHash attrPath <|> pure ""
+    newRev <- Nix.getAttr Nix.Raw "rev" attrPath <|> pure ""
     newVerMay <- rightMay `fmapRT` (lift $ runExceptT $ Nix.getAttr Nix.Raw "version" attrPath)
 
     tryAssert
@@ -341,8 +343,9 @@ updateAttrPath log updateEnv@UpdateEnv {..} mergeBaseOutpathsContext attrPath =
     -- Sanity checks to make sure the PR is worth opening
     unless hasUpdateScript do
       when (derivationContents == updatedDerivationContents) $ throwE "No rewrites performed on derivation."
-      when (oldSrcUrl == newSrcUrl) $ throwE "Source url did not change. "
-      when (oldHash == newHash) $ throwE "Hashes equal; no update necessary"
+      when (oldSrcUrl /= "" && oldSrcUrl == newSrcUrl) $ throwE "Source url did not change. "
+      when (oldHash /= "" && oldHash == newHash) $ throwE "Hashes equal; no update necessary"
+      when (oldRev /= "" && oldRev == newRev) $ throwE "rev equal; no update necessary"
     editedOutpathSet <- if calcOutpaths then currentOutpathSet else return $ dummyOutpathSetAfter attrPath
     let opDiff = S.difference mergeBaseOutpathSet editedOutpathSet
     let numPRebuilds = numPackageRebuilds opDiff
@@ -432,7 +435,7 @@ publishPackage log updateEnv oldSrcUrl newSrcUrl attrPath result opDiff rewriteM
   isBroken <- Nix.getIsBroken attrPath
   when
     (batchUpdate . options $ updateEnv)
-    (lift untilOfBorgFree)
+    (lift (untilOfBorgFree log))
   let prMsg =
         prMessage
           updateEnv
@@ -620,8 +623,8 @@ prMessage updateEnv isBroken metaDescription metaHomepage metaChangelog rewriteM
 jqBin :: String
 jqBin = fromJust ($$(envQ "JQ") :: Maybe String) <> "/bin/jq"
 
-untilOfBorgFree :: MonadIO m => m ()
-untilOfBorgFree = do
+untilOfBorgFree :: MonadIO m => (Text -> IO ()) -> m ()
+untilOfBorgFree log = do
   stats <-
     shell "curl -s https://events.nix.ci/stats.php" & readProcessInterleaved_
   waiting <-
@@ -629,8 +632,9 @@ untilOfBorgFree = do
       & readProcessInterleaved_
       & fmap (BSL.readInt >>> fmap fst >>> fromMaybe 0)
   when (waiting > 2) $ do
+    liftIO $ log ("Waiting for OfBorg: https://events.nix.ci/stats.php's evaluator.messages.waiting = " <> tshow waiting)
     liftIO $ threadDelay 60000000
-    untilOfBorgFree
+    untilOfBorgFree log
 
 assertNotUpdatedOn ::
   MonadIO m => UpdateEnv -> FilePath -> Text -> ExceptT Text m ()
diff --git a/src/Version.hs b/src/Version.hs
index 7b46d76..9732538 100644
--- a/src/Version.hs
+++ b/src/Version.hs
@@ -56,8 +56,13 @@ clearBreakOn boundary string =
 --
 -- >>> versionCompatibleWithPathPin "nodejs-slim-10_x" "10.12.0"
 -- True
+--
+-- >>> versionCompatibleWithPathPin "firefox-esr-78-unwrapped" "91.1.0esr"
+-- False
 versionCompatibleWithPathPin :: Text -> Version -> Bool
 versionCompatibleWithPathPin attrPath newVer
+  | "-unwrapped" `T.isSuffixOf` attrPath =
+    versionCompatibleWithPathPin (T.dropEnd 10 attrPath) newVer
   | "_x" `T.isSuffixOf` T.toLower attrPath =
     versionCompatibleWithPathPin (T.dropEnd 2 attrPath) newVer
   | "_" `T.isInfixOf` attrPath =