Caution about Thunderbird 52 and binary extensions

Tanstaafl tanstaafl at
Wed Nov 16 20:10:35 UTC 2016

One question - how do you tell if an Extension you are using is a binary

On 11/16/2016 1:06 PM, R Kent James <kent at> wrote:
> For a long time now, we have planned to stop supporting binary
> extensions in Thunderbird 52. Binary extensions have been disabled in
> Firefox for awhile now, and it has become increasingly untenable to
> maintain that capability in Thunderbird.
> Currently, the only known active users of binary extensions have all
> been with extensions close to the core project: Lightning, ExQuilla, and
> some Chat extensions. All of these groups gave been pursuing other
> options, though it is not clear if the options are entirely problem free.
> In mozilla core, bug 1314955 exists which intends to completely remove
> the capability for binary extensions from the core code. That bug was
> originally planned to land in gecko 52, but it missed the deadline and
> landed instead in gecko 53 (but was backed out, presumably temporarily,
> due to testing regressions). Even if it lands in mozilla-esr52, we would
> still presumably have the option of backing it out in the branch of
> m-esr52 that we will use to build TB 52.
> Some may have the hope that we could continue to support binary
> extensions in TB 52 if bug 1314955 does not land in mozilla-esr52. I
> just want to point out that it is more complicated than just that bug.
> In additional to maintaining the capability, binary compatibility also
> relies on a commitment to maintain stability of interfaces and exported
> symbols over the lifetime of the product in security updates. There was
> a weak commitment to this from the Firefox maintainers in mozilla-esr45,
> but there will be zero commitment to this in mozilla-esr52.
> Maintaining binary compatibility in Thunderbird 52 would require a
> commitment from the comm-esr52 manager (presumably to be Jörg) that we
> will watch for interface and export changes in mozilla-esr52, and
> prepare corrected versions of those bugs for our version branch of
> mozilla-esr52 that would be safe for binary compatibility. This would
> not be a trivial commitment, and I would recommend against that.
> We have not yet landed any changes to comm-central that specifically
> disable binary extensions. I think though that we should do that, and
> land in the comm train that leads to TB 52, so that we are forced to
> face reality.
> Or is someone prepared to argue that we should attempt to maintain
> binary extension compatibility in Thunderbird 52?
> :rkent

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