$ git clone -n https://src.fedoraproject.org/rpms/golang-github-rogpeppe-internal.git /var/lib/mock/f40-build-1504148-23883/root/chroot_tmpdir/scmroot/golang-github-rogpeppe-internal
Cloning into '/var/lib/mock/f40-build-1504148-23883/root/chroot_tmpdir/scmroot/golang-github-rogpeppe-internal'...
$ git fetch origin 475196c0f5d5e6433ee809958f293e371c9b0d41:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-rogpeppe-internal
 * [new ref]         475196c0f5d5e6433ee809958f293e371c9b0d41 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 475196c Update to 1.12.0