$ git clone -n https://src.fedoraproject.org/rpms/golang-github-prometheus-exporter-toolkit.git /var/lib/mock/f39-build-1919177-42938/root/chroot_tmpdir/scmroot/golang-github-prometheus-exporter-toolkit
Cloning into '/var/lib/mock/f39-build-1919177-42938/root/chroot_tmpdir/scmroot/golang-github-prometheus-exporter-toolkit'...
$ git fetch origin f3a8ff4a5c31b4eeebe77593c08d7eb4ef0be120:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-prometheus-exporter-toolkit
 * [new ref]         f3a8ff4a5c31b4eeebe77593c08d7eb4ef0be120 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f3a8ff4 Add required extra files