$ git clone -n https://src.fedoraproject.org/rpms/thunderbird.git /var/lib/mock/f39-build-2264352-54542/root/chroot_tmpdir/scmroot/thunderbird
Cloning into '/var/lib/mock/f39-build-2264352-54542/root/chroot_tmpdir/scmroot/thunderbird'...
$ git fetch origin 56d388f69870b94eb503139137aab5f93e323ddf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/thunderbird
 * [new ref]         56d388f69870b94eb503139137aab5f93e323ddf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 56d388f Update to 115.6.1