$ git clone -n https://src.fedoraproject.org/rpms/R-AsioHeaders.git /var/lib/mock/f41-build-side-1-3142735-40009/root/chroot_tmpdir/scmroot/R-AsioHeaders
Cloning into '/var/lib/mock/f41-build-side-1-3142735-40009/root/chroot_tmpdir/scmroot/R-AsioHeaders'...
$ git fetch origin ca215091cfc1433f53152bf1cdfd04d8a95555e4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-AsioHeaders
 * [new ref]         ca215091cfc1433f53152bf1cdfd04d8a95555e4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca21509 Update to latest version