We need to detect "git apply" failures reliably when patches
fail. This is necessary for solving for blob
81c1164ae5 in
https://public-inbox.org/git/ when at least two messages can
solve for it (and one of them fails):
1. https://public-inbox.org/git/
b9fb52b8-8168-6bf0-9a72-
1e6c44a281a5@oracle.com/
2. https://public-inbox.org/git/
56664222-6c29-09dc-ef78-
7b380b113c4a@oracle.com/