Likely timing of future Thunderbird Gecko builds

[R Kent James]

On 4/18/2017 12:57 PM, Magnus Melin wrote:
> There might be some more breakage around 57 when extension-only code 
> can be removed

"Some more breakage" as in all of our addons no longer work? What do you 
think we are going to do at that point? We have three choices: 1) stop 
supporting XUL addons, 2) convince Mozilla to NOT remove the code we 
need, or 3) start building from a mozilla-central branch (or 
compile-time code branches), as we have done in TB 38, TB 45, and TB 52 
for the last two years. I don't see 1) or 2) as viable, so 3) WILL 
happen. I really don't understand why that is so controversial, to me it 
is just planning ahead for an inevitable future. Thunderbird did not die 
when we started building TB 38 and TB 45 from mozilla branches, not will 
it end when we start building TB 57 and greater from a mozilla branch at 
the point when maintaining mozilla-central compatibility forces 
compromises we are not willing to make (like abandoning XUL addons).

I don't believe that talk of how quickly Thunderbird will die when we 
branch, nor hope that we will muddle through somehow, are particularly 
helpful. Our community could benefit from some concrete planning here. 
Also the Thunderbird 38 and 45 branches were enormously helpful in 
removing pressure from mozilla-esr maintainers to accept patches that 
Firefox did not want but Thunderbird needed.

:rkent