$ git clone -n https://src.fedoraproject.org/rpms/composer.git /var/lib/mock/f45-build-5083-337/root/chroot_tmpdir/scmroot/composer
Cloning into '/var/lib/mock/f45-build-5083-337/root/chroot_tmpdir/scmroot/composer'...
$ git fetch origin 08650845f05c801fe98947068f1be14a5e5e8b35:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/composer
 * [new ref]         08650845f05c801fe98947068f1be14a5e5e8b35 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0865084 v2.10.3