elif backport_ext_candidates:
if len(backport_ext_candidates)>1:
print "Warning: multiple backport extension candidates: %s"%(" ".join(e.name for e in backport_ext_candidates))
elif backport_ext_candidates:
if len(backport_ext_candidates)>1:
print "Warning: multiple backport extension candidates: %s"%(" ".join(e.name for e in backport_ext_candidates))