$ git clone -n https://src.fedoraproject.org/rpms/webkit2-sharp.git /var/lib/mock/f39-build-1898868-42816/root/chroot_tmpdir/scmroot/webkit2-sharp
Cloning into '/var/lib/mock/f39-build-1898868-42816/root/chroot_tmpdir/scmroot/webkit2-sharp'...
$ git fetch origin 067b123780a689c2572bf89203ce63be68c0dd6a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/webkit2-sharp
 * [new ref]         067b123780a689c2572bf89203ce63be68c0dd6a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 067b123 fix FTBFS: apply patch to generated file replacing parentinstance with parent