$ git clone -n https://src.fedoraproject.org/rpms/rubygem-capybara.git /var/lib/mock/f42-build-3458052-45512/root/chroot_tmpdir/scmroot/rubygem-capybara
Cloning into '/var/lib/mock/f42-build-3458052-45512/root/chroot_tmpdir/scmroot/rubygem-capybara'...
$ git fetch origin 23ab8b00ab7f01c33e863e6e94a87e4652d922da:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-capybara
 * [new ref]         23ab8b00ab7f01c33e863e6e94a87e4652d922da -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 23ab8b0 Update to Capybara 3.40.0.