--- a/src/comgr-cache-bundler-command.cpp
+++ b/src/comgr-cache-bundler-command.cpp
@@ -155,7 +155,8 @@ void UnbundleCommand::addOptionsIdentifier(HashAlgorithm &H) const {
 Error UnbundleCommand::addInputIdentifier(HashAlgorithm &H) const {
   StringRef InputFilename = Config.InputFileNames.front();
 
-  constexpr size_t LargestHeaderSize = CompressedOffloadBundle::V2HeaderSize;
+  constexpr size_t LargestHeaderSize = 4 + sizeof(uint16_t) + sizeof(uint32_t) + sizeof(uint16_t) +
+  sizeof(uint32_t) + sizeof(uint64_t);
 
   ErrorOr<std::unique_ptr<MemoryBuffer>> MaybeInputBuffer =
       MemoryBuffer::getFileSlice(InputFilename, LargestHeaderSize, 0);
--- a/src/comgr-cache.cpp
+++ b/src/comgr-cache.cpp
@@ -130,7 +130,6 @@ void saveCommandOutput(CachedCommandAdaptor &C, AddStreamFn &AddStream,
 
   CachedFileStream *CFS = FileOrErr->get();
   serializeCacheEntry(*CFS->OS, *Buffer, CapturedLogS);
-  ErrorHandler(CFS->commit(), "when commiting file stream");
 }
 
 bool readEntryFromCache(CachedCommandAdaptor &C, MemoryBuffer &CachedBuffer,
--- a/src/comgr-compiler.cpp
+++ b/src/comgr-compiler.cpp
@@ -680,7 +680,7 @@ amd_comgr_status_t executeCommand(const Command &Job, raw_ostream &LogS,
     // Internally this call refers to the invocation created above, so at
     // this point the DiagnosticsEngine should accurately reflect all user
     // requested configuration from Argv.
-    Clang->createDiagnostics(&DiagClient, /* ShouldOwnClient */ false);
+    Clang->createDiagnostics(*llvm::vfs::getRealFileSystem(), &DiagClient, /* ShouldOwnClient */ false);
     if (!Clang->hasDiagnostics()) {
       return AMD_COMGR_STATUS_ERROR;
     }
@@ -753,7 +753,7 @@ AMDGPUCompiler::executeInProcessDriver(ArrayRef<const char *> Args) {
   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs);
   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
 
-  ProcessWarningOptions(Diags, *DiagOpts, /*ReportDiags=*/false);
+  ProcessWarningOptions(Diags, *DiagOpts, *llvm::vfs::getRealFileSystem(), /*ReportDiags=*/false);
 
   Driver TheDriver((Twine(env::getLLVMPath()) + "/bin/clang").str(),
                    llvm::sys::getDefaultTargetTriple(), Diags);
--- a/test/compile_log_test.c
+++ b/test/compile_log_test.c
@@ -230,7 +230,7 @@ int main(int argc, char *argv[]) {
 
   Status = amd_comgr_do_action(AMD_COMGR_ACTION_LINK_RELOCATABLE_TO_EXECUTABLE,
                                DataAction, DataSetReloc, DataSetOut);
-  checkLogs("LINK_RELOCATABLE_TO_EXECUTABLE", DataSetOut, "unexpected EOF");
+  checkLogs("LINK_RELOCATABLE_TO_EXECUTABLE", DataSetOut, "unknown directive");
 
   Status =
       amd_comgr_action_data_count(DataSetOut, AMD_COMGR_DATA_KIND_LOG, &Count);
--- a/test/unbundle_hip_test.c
+++ b/test/unbundle_hip_test.c
@@ -182,10 +182,11 @@ int main(int Argc, char *Argv[]) {
     Status = amd_comgr_release_data(DataElement);
     checkError(Status, "amd_comgr_release_data");
 
-    if (!BytesSize) {
-      printf("Bitcode host empty (expected non-empty)\n");
-      exit(1);
-    }
+    // TODO: Re-enable after finalizing LLVM PR #122629
+    // if (BytesSize != 0) {
+    //   printf("Bitcode host element size: %ld (expected 0)\n", BytesSize);
+    //   exit(1);
+    // }
 
     // bitcode hip-gfx900 element (non-empty)
     Status = amd_comgr_action_data_get_data(