Bug info: bug 833117, FreeBSD Port www/firefox, glib20 2.36.3 and clang-devel 3.4.r182968

[Robert Burmeister]

https://bugzilla.mozilla.org/show_bug.cgi?id=833117
> FireFox 22 fails to launch as described in the bug report after updating 
> glib20 to version 2.36.3.
> My copy of the Epiphany browser is built on libxul 17.0.7, which still works, 
> as does Thunderbird 17.0.7.
I have been able to distill out more information on the error, which acts like 
Mozilla bug 833117.

I am using:
FreeBSD i386 9.2-BETA2 #0 r253950 (compiled with -O2)
clang-devel 3.4.r182968
firefox 23.0,1

I have been using compile options -O2 for the base system, and -O3 via 
OPTIMIZED_CFLAGS=on for FireFox, for years without issue.

I have recently been using the latest clang-devel to overcome issues building 
LibreOffice, (which have likely been fixed in base Clang by now),
gcc 4.6.3, and base gcc 4.2.1; with each compiler used as requested by the port. 
(www/firefox invokes Clang)

With the glib20 update to version 2.36.3, the symptoms of Mozilla bug 833117 
manifested for FireFox 2x but not 1.7 esr.

I have since eliminated the spurious errors related to the glib20 upgrade.

The [ GLib-CRITICAL **: g_slice_set_config: assertion `sys_page_size == 0' 
failed ] error discussed earlier appears to be a red herring,
as it still appears when starting FireFox 23 even when the bug does not manifest.


I have isolated that building www/firefox with OPTIMIZED_CFLAGS invoking -O3 
causes bug 833117 to manifest,
while building www/firefox with -O2 in make.conf allows FireFox to work normally.

The root cause appears to be a compiler optimization issue.