$ git clone -n https://src.fedoraproject.org/rpms/golang-github-opentracing-basictracer.git /var/lib/mock/f41-build-1036214-18712/root/chroot_tmpdir/scmroot/golang-github-opentracing-basictracer
Cloning into '/var/lib/mock/f41-build-1036214-18712/root/chroot_tmpdir/scmroot/golang-github-opentracing-basictracer'...
$ git fetch origin 8203afcb5f1a5c85056521644520d7f5daef7456:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-opentracing-basictracer
 * [new ref]         8203afcb5f1a5c85056521644520d7f5daef7456 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8203afc Fix FTBFS