###!!! ASSERTION: DoContent returned no listener?: 'abort || m_targetStreamListener', file uriloader/base/nsURILoader.cpp, line 776 ###!!! ASSERTION: OnDataAvailable implementation consumed no data: 'Error', file netwerk/base/src/nsInputStreamPump.cpp, line 531

This assertion fires for me running reftests on Japanese Windows 7. layout/reftests/bugs/reftest.list == 249141.xul 249141-ref.xul WARNING: NS_ENSURE_SUCCESS(docLoaderFactory->CreateInstance("view", aOpenedChannel, aLoadGroup, aContentType, static_cast<nsIContentViewerContainer*>(this), 0L, aContentHandler, aViewer), ((nsresult) 0x80004005L)) failed with result 0x80004005: file c:/builds/mozcentral/docshell/base/nsDocShell.cpp, line 7484 ###!!! ASSERTION: DoContent returned no listener?: 'abort || m_targetStreamListener', file c:/builds/mozcentral/uriloader/base/nsURILoader.cpp, line 776 ###!!! ASSERTION: OnDataAvailable implementation consumed no data: 'Error', file c:/builds/mozcentral/netwerk/base/src/nsInputStreamPump.cpp, line 531

Presumably running them against some random profile, not the profile the test harness generates, right?

Yes, running reftests via -reftest command-line option with default profile options. Are reftests now required to be run with a specific profile?

If you want the XUL ones to actually test anything, yes. (Though there may be other things that also depend on that profile at this point.)

Yes, you should use "make reftest" now. It sets up a profile with options such as enabling untrusted XUL, starts a web server (for "HTTP" tests), and post-processes some of Firefox's output.

I've hit this assertion as well during fuzz testing, even with remote content (where you should instead be getting the "XUL is no longer supported" page. Will this be fixed at some point?

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258