Intermittent failure on gonk builder: "execvp: ./host_jskwgen: Permission denied"

[eefriedman]

Seen in #8408, #8394.

--- stderr
/home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: 1: /home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: /home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/../../python/mozbuild/mozbuild/milestone.py: Permission denied
/home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: 1: /home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: /home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/../../python/mozbuild/mozbuild/milestone.py: Permission denied
/home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: 1: /home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: /home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/../../python/mozbuild/mozbuild/milestone.py: Permission denied
/home/servo/.cargo/git/checkouts/mozjs-06d7f04b6dbb8a8e/master/mozjs/js/src/configure: 8887: test: Illegal number: 
Reticulating splines...
Finished reading 34 moz.build files in 0.06s
Processed into 115 build config descriptors in 0.04s
Backend executed in 0.18s
80 total backend files; 80 created; 0 updated; 0 unchanged; 0 deleted; 10 -> 20 Makefile
Total wall time: 0.31s; CPU time: 0.25s; Efficiency: 80%; Untracked: 0.04s
make[4]: execvp: ./host_jskwgen: Permission denied
make[4]: *** [/home/servo/buildbot/slave/gonk/build/target/arm-linux-androideabi/debug/build/mozjs_sys-e411d274df144795/out/js/src/jsautokw.h] Error 127
make[3]: *** [js/src/target] Error 2
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [compile] Error 2
make[1]: *** [default] Error 2
make: *** [all] Error 2

Not sure what's going on; my first guess would be a parallel build gone wrong, but that's just a blind guess.

[larsbergstrom]

seen in the wild here, too - #7688

[larsbergstrom]

OK, think I found this - it's a known intermittent, fixed upstream:
https://bugzilla.mozilla.org/show_bug.cgi?id=1146738
https://hg.mozilla.org/mozilla-central/rev/734e468e8274

An SMup should fix this.

[eefriedman]

Can we cherry-pick the fix? This has gotten to be really annoying, and upgrading SpiderMonkey isn't something we do frequently.

[larsbergstrom]

@eefriedman I'd be fine with that, especially since it's super-trivial.

@jdm @michaelwu Would it be OK with you for us to cherry-pick this configure change to hopefully avoid the build race?

[michaelwu]

I'm ok with it.

[jdm]

Yes yes yes.

[larsbergstrom]

This should have been closed by servo/mozjs#63 and #8510