$ git clone -n https://src.fedoraproject.org/rpms/mailimporter.git /var/lib/mock/f45-build-17959-506/root/chroot_tmpdir/scmroot/mailimporter
Cloning into '/var/lib/mock/f45-build-17959-506/root/chroot_tmpdir/scmroot/mailimporter'...
$ git fetch origin 7b335a0cd8faeb48b0195e246eee123a9d78ab85:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mailimporter
 * [new ref]         7b335a0cd8faeb48b0195e246eee123a9d78ab85 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7b335a0 26.08.1