git bisect start '--first-parent'
# status: waiting for both good and bad commits
# bad: [6333ec434907a3bfb00afc4bd35f2b929432dba2] Merge remote-tracking branch 'upstream/2.3'
git bisect bad 6333ec434907a3bfb00afc4bd35f2b929432dba2
# status: waiting for good commit(s), bad commit known
# good: [b4ef3e05cdf9496ba0f0e1215b10bd1379b26829] Merge pull request #2810 from xerus2000/trackset-capability
git bisect good b4ef3e05cdf9496ba0f0e1215b10bd1379b26829
# bad: [441e49cf4265cfcf7bc056d091759bd6773c6131] Merge pull request #2682 from Be-ing/migrate-to-QJSEngine
git bisect bad 441e49cf4265cfcf7bc056d091759bd6773c6131
# first bad commit: [441e49cf4265cfcf7bc056d091759bd6773c6131] Merge pull request #2682 from Be-ing/migrate-to-QJSEngine