$ git clone -n https://src.fedoraproject.org/rpms/thunderbird.git /var/lib/mock/f41-build-1041925-18994/root/chroot_tmpdir/scmroot/thunderbird
Cloning into '/var/lib/mock/f41-build-1041925-18994/root/chroot_tmpdir/scmroot/thunderbird'...
$ git fetch origin 44976791ef7f67dc167fd0957c9532eeef99949c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/thunderbird
 * [new ref]         44976791ef7f67dc167fd0957c9532eeef99949c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4497679 Update to 115.12.0