User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:66.0) Gecko/20100101 Firefox/66.0

Steps to reproduce:

Compile firefox.

./mach build

Actual results:

gcc: error: unrecognized command line option '-Qunused-arguments'; did you mean '-Wunused-parameter'?

This error does not show up using gcc-8.2 .

Expected results:

The right parameter should have being passed to gcc-8.3

This error does not show up using gcc-8.2 .

Please provide the mozconfig you're using to compile Firefox, as well as the output of ./mach build.

ac_add_options --prefix=/opt/firefox-66.0b13
ac_add_options --enable-hardening"

ac_add_options --enable-application=browser
ac_add_options --enable-official-branding
ac_add_options --disable-tests

#ac_add_options --enable-webrender=build
#ac_add_options --disable-webspeech
#ac_add_options --disable-webspeechtestbackend

ac_add_options --x-includes=/usr/X11/include
ac_add_options --x-libraries=/usr/X11/lib

ac_add_options --enable-pulseaudio
ac_add_options --enable-alsa
ac_add_options --disable-clang-plugin

ac_add_options --enable-system-sqlite
ac_add_options --with-system-libevent
ac_add_options --with-system-libvpx
ac_add_options --with-system-icu
ac_add_options --enable-system-ffi

ac_add_options --with-system-nspr
ac_add_options --with-system-nss
ac_add_options --enable-system-pixman
#ac_add_options --enable-system-cairo
#ac_add_options --with-system-jpeg

ac_add_options --enable-libjpeg-turbo
ac_add_options --with-system-bz2
ac_add_options --with-system-png
ac_add_options --with-system-zlib

mk_add_options PYTHON=/usr/bin/python3
mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/firefox-build-dir

I don't know how to include 54K of text, so here are the last lines from ./mach build

0:11.18 js/src> checking for C++ dynamic_cast to void*... (cached) no
0:11.18 js/src> checking for __thread keyword for TLS variables... (cached) yes
0:11.18 js/src> checking for localeconv... (cached) yes
0:11.19 js/src> checking NSPR selection... command-line
0:11.21 js/src> checking for valid optimization flags... yes
0:11.21 js/src> checking for __cxa_demangle... (cached) yes
0:11.22 js/src> checking for -pipe support... yes
0:11.24 js/src> checking for tm_zone tm_gmtoff in struct tm... yes
0:11.28 js/src> checking what kind of list files are supported by the linker... configure: error: Couldn't find one that works
0:11.28 js/src> ERROR: old-configure failed
0:11.32 *** Fix above errors and then restart with
0:11.32 "./mach build"
0:11.32 make: *** [client.mk:115: configure] Error 1

/sources/firefox66/firefox-66.0/firefox-build-dir/config.log:

..
configure:3246: checking for connect
configure:3342: checking for remove
configure:3438: checking for shmat
configure:3543: checking for IceConnectionNumber in -lICE
configure:3716: /usr/bin/cc -pipe -m64 -march=native -std=gnu99 -c conftest.c 1>&5
configure: In function 'main':
configure:3712:15: error: 'thumb2' undeclared (first use in this function)
configure:3712:15: note: each undeclared identifier is reported only once for each function it appears in
configure: failed program was:
#line 3709 "configure"
#include "confdefs.h"

int main() {
return sizeof(thumb2);
; return 0; }
configure:4532: /usr/bin/cc -pipe -m64 -march=native -std=gnu99 -o conftest -Qunused-arguments conftest.c 1>&5
cc: error: unrecognized command line option '-Qunused-arguments'; did you mean '-Wunused-parameter'?
configure: failed program was:
#line 4525 "configure"
#include "confdefs.h"

int main() {

; return 0; }
configure: error: compiler is incompatible with sanitize options