found via bughunter topsite tests and reproduced via latest stylo build from tinderbox Steps to reproduce: --> Load http://www.infusionsoft.com ---> Assertion failure WARN:geckoservo::glue: Resolving style on unstyled element with lazy computation forbidden. Assertion failure: pseudoContext (should have taken the ReconstructFrame path above), at /home/worker/workspace/build/src/layout/base/ServoRestyleManager.cpp:250

another site where bughunter running into this is also siemens.com

After my fix to animation parsing, this appears in layout/reftests/bugs/367220-1.html as well. I have no idea why.

So this means that, while restyling an element, its ::before pseudo disappeared (there are no rules matching for it), yet we didn't get a ReconstructFrame hint? Xidorn, can you reproduce with the patch over bug 1344104 applied?

(In reply to Emilio Cobos Álvarez [:emilio] from comment #3) > Xidorn, can you reproduce with the patch over bug 1344104 applied? Yes, I can still reproduce it with that patch.

I'm fixing up this kind of pseudo stuff in bug 1331047 (which is taking forever to finish, but slowly making progress). If that's the only test that fails with your animation changes, feel free to disable the test, and file a bug dependent on bug 1331047.

This seems to work now.