$ git clone -n https://src.fedoraproject.org/rpms/magic.git /var/lib/mock/f40-build-790555-136608/root/chroot_tmpdir/scmroot/magic
Cloning into '/var/lib/mock/f40-build-790555-136608/root/chroot_tmpdir/scmroot/magic'...
$ git fetch origin 35c34519d3ab84f9f47543e1673aef02876960f0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/magic
 * [new ref]         35c34519d3ab84f9f47543e1673aef02876960f0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 35c3451 8.3.462