This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
Due to a bug in Apache 2 (see the URL), checklink doesn't work with it, affected versions are AFAICT all up to 2.0.43. Since major OS distributions are shipping Apache versions that are affected by the bug, this should be worked around in checklink, perhaps by removing the DEBUG command line arg stuff.
Done, by removing the debug logic and reworking the decision whether we're running as a CGI or from the command line.