$ git clone -n https://src.fedoraproject.org/rpms/rubygem-rspec-core.git /var/lib/mock/f39-build-1507910-35318/root/chroot_tmpdir/scmroot/rubygem-rspec-core
Cloning into '/var/lib/mock/f39-build-1507910-35318/root/chroot_tmpdir/scmroot/rubygem-rspec-core'...
$ git fetch origin 01442efdd9c4f688d746bac0cb303130421b7ed1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-rspec-core
 * [new ref]         01442efdd9c4f688d746bac0cb303130421b7ed1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 01442ef Fix one failing test related to thread local variable