Firefox segfaults if no fonts are installed

[coypu%SDF.ORG@localhost]

Fresh install of NetBSD 6.1.5 on amd64.
Firefox (38.0.5 from pkgsrc) does not work after install 
before installing truetype fonts.

I receive the following message:

$ firefox

(process:2226): GLib-CRITICAL **: g_slice_set_config: 
assertion 'sys_page_size == 0' failed
Segmentation fault (core dumped)

For the sake of others who may be having this issue, 
this 
is what happens when I run it in gdb:

(gdb) run
Starting program: /usr/pkg/bin/firefox 

(process:2046): GLib-CRITICAL **: g_slice_set_config: 
assertion 'sys_page_size == 0' failed

Program received signal SIGSEGV, Segmentation fault.
[Switching to LWP 1]
0x00007f7feee49a4a in ?? () from 
/usr/pkg/lib/firefox/libxul.so
(gdb) bt
#0  0x00007f7feee49a4a in ?? () from 
/usr/pkg/lib/firefox/libxul.so
#1  0x00007f7feed61515 in ?? () from 
/usr/pkg/lib/firefox/libxul.so
#2  0x00007f7feed6177c in ?? () from 
/usr/pkg/lib/firefox/libxul.so

And so on.

This issue occurs whenever you do not have truetype fonts 
installed, and is resolved by installing packages like 
mozilla-fonts or dejavu-ttf.

I think this package should have a dependency on a 
truetype font.

It took me a while to figure out that this is the issue 
as the error message does not hint at this direction at all.