i have kernel 5.5.1-1-ARCH armv7l
from peach pi on chromebook snow

firmware also from there and modules.

slackware arm binutils 2.33.1
glibc-2.30
gcc-9.2.0

i was having hit and misses with building especially through the sixty versions of firefox and 71 too.
This finally built correctly since I use a slackbuild official firefox from slackware and will have to use nodejs within 10 something if you try to build firefox 75 approximately.

it does have a launch bug where /dev/shm it can't write to but if you atke a look at this:

http://forums.mozillazine.org/viewto...f=38&t=3044432