$ git clone -n https://src.fedoraproject.org/rpms/rubygem-typhoeus.git /var/lib/mock/f41-build-1197202-22336/root/chroot_tmpdir/scmroot/rubygem-typhoeus
Cloning into '/var/lib/mock/f41-build-1197202-22336/root/chroot_tmpdir/scmroot/rubygem-typhoeus'...
$ git fetch origin da6dee7bbe088665aba81e27f309fb1ea5ab777e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-typhoeus
 * [new ref]         da6dee7bbe088665aba81e27f309fb1ea5ab777e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at da6dee7 Eliminate use of obsolete %patchN syntax (#2283636)