$ git clone -n https://src.fedoraproject.org/rpms/cpp-jwt.git /var/lib/mock/f40-build-2587869-62519/root/chroot_tmpdir/scmroot/cpp-jwt
Cloning into '/var/lib/mock/f40-build-2587869-62519/root/chroot_tmpdir/scmroot/cpp-jwt'...
$ git fetch origin 020f405fc5336b757032d21e234d64592a8fc214:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cpp-jwt
 * [new ref]         020f405fc5336b757032d21e234d64592a8fc214 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 020f405 fix spec file syntax for el8