Bug#973414: libmozjs-78-0: invalid opcodes in libmozjs when launching GDM3

[Martin-Éric Racine]

ma 9. marrask. 2020 klo 20.05 Martin-Éric Racine
(martin-eric.racine at iki.fi) kirjoitti:
>
> su 8. marrask. 2020 klo 14.40 Simon McVittie (smcv at debian.org) kirjoitti:
> > Because your syslog also included similar crashes in librsvg, which is
> > unrelated to mozjs except that both involve Rust code, I wonder whether
> > it might be the rust compiler rather than mozjs' JIT that is emitting
> > non-i586 opcodes on x86?
>
> Good observation. I'd really like to know this as well.
>
> Worse comes, if it indeed turns out that libmozjs doesn't support
> non-PAE hosts anymore, I could easily switch to lightdm or lxdm.
> However, without librsvg, pretty much all display managers break,
> since they all use the default SVG background configured by
> desktop-base.

Having downgraded and pinned all librsvg2 packages to what's in
oldstable (2.40.16) restores GDM's fallback to Xorg at least enough to
display gnome-session-failed. I suspect that the only bit of failure
that's left is because of mozjs, which unfortunately cannot be
downgraded, because it's a versioned dependency for a number of
packages. This would suggest that the problem indeed is with the Rust
compiler.

I'd really love to hear from Rust's maintainer at this point.

Martin-Éric