Marin Jansa noted that when do_patch fails during a build, the stack trace is enormous and unnecessary: "A simple message that patch_do_patch failed because patch wasn't found or didn't apply without python trace would be much better."
Fix merged in revision 11e5d7bc814a265d338dbb06d82e7533c2187be2.
I tested with latest master commit cb89d43473a91ff4cb2447d642fcd9308d7366e3, the feature could work.