$ git clone -n https://src.fedoraproject.org/rpms/golang-github-opentracing-contrib-grpc.git /var/lib/mock/f38-build-side-42-init-devel-667310-26654/root/chroot_tmpdir/scmroot/golang-github-opentracing-contrib-grpc
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-667310-26654/root/chroot_tmpdir/scmroot/golang-github-opentracing-contrib-grpc'...
$ git fetch origin 287f3ce49e1ec3817c2a50797c2a02a44b575aef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-opentracing-contrib-grpc
 * [new ref]         287f3ce49e1ec3817c2a50797c2a02a44b575aef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 287f3ce Rebuild to fix FTBFS