$ git clone -n https://src.fedoraproject.org/rpms/cpprest.git /var/lib/mock/f41-build-831207-156851/root/chroot_tmpdir/scmroot/cpprest
Cloning into '/var/lib/mock/f41-build-831207-156851/root/chroot_tmpdir/scmroot/cpprest'...
$ git fetch origin 52871183c6cdcf14b17deaa38068943fe6fac6ac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cpprest
 * [new ref]         52871183c6cdcf14b17deaa38068943fe6fac6ac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5287118 Add dependency on openssl-devel-engine