$ git clone -n https://src.fedoraproject.org/rpms/rubygem-webmock.git /var/lib/mock/f40-build-2285925-55696/root/chroot_tmpdir/scmroot/rubygem-webmock
Cloning into '/var/lib/mock/f40-build-2285925-55696/root/chroot_tmpdir/scmroot/rubygem-webmock'...
$ git fetch origin 77719fab64c34cb17644925754a6d42ab2d3ab10:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-webmock
 * [new ref]         77719fab64c34cb17644925754a6d42ab2d3ab10 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77719fa Update to WebMock 3.18.1.