The bug that mashed Firefox 71 (ultimately fallout from bug 1601707 and its many dupes) did not get fixed in time for Firefox 72 and turned out to be a compiler issue. The lifetime change that the code in question relies upon is in Clang 7 and up, but not yet in gcc, and unless you are using a pre-release build this fix is not (yet) in any official release of gcc 9 or 10. As Clang is currently unable to completely build the browser on ppc64le, if your extensions are affected (mine aren't) you may want to add this patch which was also landed on the beta release channel for Firefox 73.
The debug and opt configurations are, again, otherwise unchanged from Firefox 67.