It also breaks Cinnamon:
Window manager warning: Log level 32: Execution of main.js threw
exception: JS_EvaluateScript() failed
Traceback (most recent call last):
File "/usr/bin/cinnamon-launcher", line 36, in <module>
os.execvp(FALLBACK_COMMAND, (FALLBACK_COMMAND,) + FALLBACK_ARGS)
File "/usr/lib/python2.7/os.py", line 346, in execvp
_execvpe(file, args)
File "/usr/lib/python2.7/os.py", line 382, in _execvpe
func(fullname, *argrest)
After downgrading libmozjs-24 all is ok again. Please take a look at it.