Allow unloading of Transactions that have not been committed:
Allow unloading of Transactions that have not been committed:

If Lookup fails to instantiate, its transaction should not be committed,
as we know it's useless and must be unloaded as it might contain invalid
Decls.
But that means Lookup needs to unload a non-committed transaction.

root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling