$ git clone -n https://src.fedoraproject.org/rpms/copr-keygen.git /var/lib/mock/f39-build-1591827-38299/root/chroot_tmpdir/scmroot/copr-keygen
Cloning into '/var/lib/mock/f39-build-1591827-38299/root/chroot_tmpdir/scmroot/copr-keygen'...
$ git fetch origin 4b58ef9574f01e2ebdd9d9f341c12fa9d5866835:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/copr-keygen
 * [new ref]         4b58ef9574f01e2ebdd9d9f341c12fa9d5866835 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4b58ef9 Update copr-keygen to 1.91-1