$ git clone -n https://src.fedoraproject.org/rpms/egl-gbm.git /var/lib/mock/f41-build-854367-166847/root/chroot_tmpdir/scmroot/egl-gbm
Cloning into '/var/lib/mock/f41-build-854367-166847/root/chroot_tmpdir/scmroot/egl-gbm'...
$ git fetch origin 84bf7cd285ec122f3ee92fda5ddb6e57207dde69:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/egl-gbm
 * [new ref]         84bf7cd285ec122f3ee92fda5ddb6e57207dde69 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 84bf7cd Add sources