[GHC DevOps Group] GHC 8.4.3 release, and release policies?

[Gershom B]

I believe this list/group is intended to help set GHC release policies
and plan when releases occur.

I'd like to draw people's attention to
https://ghc.haskell.org/trac/ghc/ticket/15068

I think that the "nay" side has the right of it.

1) To summarize my understanding: there is an issue with upstream gnu
binutils that are included in Ubuntu 18.04 and is triggered by GHC
_only_ when the -g flag for debug symbol output is passed. This bug is
triggered by GHCs going back through the 8.2 series. Note that 18.04
was released _after_ ghc 8.4.2.

There is a patch to GHC to work around this issue, that also
incidentally improves another possible issue with debug symbol
emitting.

Normally the -g flag is relatively rarely used, and by those who would
be able to work around such things. However, stack runs with -g by
default, unless users explicitly compile with symbol stripping turned
on.

The proposed solution is an 8.4.3 release of GHC with _just_ this patch.

2) To summarize my objection to the plan -- I do not think that
spinning up a full new release to just patch one thing to work around
an upstream bug is a good precedent for GHC release management. I can
imagine exceptional circumstances, but in general the right answer
should happen downstream of a full GHC release. We already want a more
timely cadence. That cadence should suffice for these sorts of things.

In the meantime, the binary provided by hvr's ubuntu ppa already
incorporates this patch.

One might say -- what about stack and platform users? My suggestion
would be that since stack provides its own binaries, patched binaries
can be provided by stack in this circumstance, just as the ubuntu ppa
includes the patch. Similarly we could respin a platform release with
the patch, just for linux, rather than across all three major
platforms. (Or not -- I don't think that users that know about -g
would mind too much using the ppa for the patched release, and I
suspect those users are more likely ppa users already anyway, or wise
enough not to immediately upgrade to a new ubuntu system for devwork
without time for bugs to shake out).

Anyway, I can't recall a precedent for a point-release over an issue
like this in the past, and I think if we start to do so too much it
will overstrain resources away from the important goals of regularity
and stability we do want in releases.

I would like to know what others think.

Cheers,
Gershom