Bug#904994: gjs: New upstream release 1.53.90, requiring mozjs60

[Simon McVittie]

On Thu, 16 Aug 2018 at 10:17:19 +0100, Simon McVittie wrote:
> Similarly, I think the ${gjs:Provides} and libgjs0-$(LIBMOZJS) thing might
> now be a relic of previous versions that can go away?
...
> #635174 was merged with #635175, which referred to gjs-internals-1.0.pc,
> which no longer exists; and gnome-shell does not directly depend on
> libmozjs-* any more, only on libgjs0g.

It looks as though gjs stopped exposing mozjs API/ABI in 1.47.0 as a result
of <https://bugzilla.gnome.org/show_bug.cgi?id=772386>, around the time of
the mozjs24 to mozjs31 transition. So it was necessary that we broke ABI
post-stretch (mozjs24/libgjs0d to mozjs{31,38,52,60}/libgjs0e), but going
from libgjs0e to libgjs0g was in fact unnecessary.

We should keep libgjs0g now, because going backwards to 0e would be
just as painful as going forwards, but libgjs.so.0 can hopefully now
remain libgjs0g forever.

If it breaks ABI again, IMO we should definitely ask upstream to
bump the SONAME (or even change the name of the library for full
parallel-installation) instead of using weird Debian pseudo-SONAMEs,
similar to the way libmutter now uses SONAMEs properly again.

    smcv