Bug#878519: gjs: doesn't seem to work on mips (at least on minkus and mips-aql-01)

Package: gjs
Version: 1.50.1-2
Severity: serious
Affects: gnome-documents
X-Debbugs-Cc: [email protected]

mozjs52 now works at least partially on mips (although there are thousands
of test failures, #878284) but gjs doesn't even start:

    (sid_mips-dchroot)smcv@minkus ~ % js52
    js> print("hello, world")
    hello, world
    js>
    (sid_mips-dchroot)smcv@minkus ~ % gjs

    (gjs:13738): Gjs-WARNING **: gjs_eval_in_scope called with a pending exception

    (gjs:13738): Gjs-WARNING **: JS ERROR: TypeError: can't assign to properties of (new Number(1.629847465960073e+237)): not an object

    JS_EvaluateScript() failed

This causes gnome-documents to FTBFS (#878431, which I can also reproduce
for 3.22.5-2 in unstable):
https://buildd.debian.org/status/fetch.php?pkg=gnome-documents&arch=mips&ver=3.26.1-1&stamp=1507913495&raw=0

I thought gjs had build-time tests, but this doesn't exactly look
thorough, so perhaps they aren't run or something:

   dh_auto_test -a
	make -j2 test VERBOSE=1
make[1]: Entering directory '/<<PKGBUILDDIR>>'
XMLLINT not set and xmllint not found in path; skipping xml preprocessing.
XMLLINT not set and xmllint not found in path; skipping xml preprocessing.
XMLLINT not set and xmllint not found in path; skipping xml preprocessing.
make[1]: Nothing to be done for 'test'.

We should at least do a smoke-test (run the interpreter with a "hello
world" program, like I added to mozjs52) to demonstrate that it has some
basic level of functionality.

As for the actual bug, sorry, I have no idea. If there isn't a
likely-looking patch in Firefox or something, we might have to go the
architecture-specific removal route, which would mean no gjs and no
task-gnome-desktop on mips. I don't imagine there are very many GNOME
users on mips...

Are the 32-bit mips ports planned to still be release architectures in
buster? How much effort is it worth putting into them?

Regards,
    smcv