For example, run-webkit-tests --force css3/flexbox doesn't open the results.html page when there are failures (currently the css3/flexbox tests are all skipped). It looks like it is generating the correct results.html file though.
I just tried this with new-run-webkit-tests --chromium --force webarchive , and it worked fine (webarchive is normally skipped). Also, I don't see anything in the code that would keep the results.html from being opened. So, maybe there was a bug that got fixed, or maybe it was something else. Please reopen if you see this again