$ git clone -n https://src.fedoraproject.org/rpms/calibre.git /var/lib/mock/f40-build-1476542-23795/root/chroot_tmpdir/scmroot/calibre
Cloning into '/var/lib/mock/f40-build-1476542-23795/root/chroot_tmpdir/scmroot/calibre'...
$ git fetch origin e15a296e0d6fe6fb08ceb98cf55ad90281d2046f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calibre
 * [new ref]         e15a296e0d6fe6fb08ceb98cf55ad90281d2046f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e15a296 Merge remote-tracking branch 'origin/main' into f40