Phobos and older DMD versions

[Dicebot]

On Tuesday, 6 August 2013 at 14:51:35 UTC, qznc wrote:
> My recent pull request [0] triggered some issue, which should 
> get a bigger discussion:
>
> Should Phobos version N also compile with DMD N-1?
>
> In my opinion it should, because it makes Phobos development 
> simpler. You don't need a self compiled dmd to fix bugs.
>
> However, reality sometimes requires exceptions. I understand 
> that sometimes Phobos uses a feature of dmd HEAD. That is why I 
> said "should", but not "must". ;)
>
>
> [0] 
> https://github.com/D-Programming-Language/phobos/pull/1454/files#r5601514

Makes no sense to me.

1) DMD and Phobos are always released at the same time and share 
versioning.
2) It will require essentially doubling the load on pull request 
tester.

As you need to be sure your fix works on current DMD head anyway, 
you should have full custom environment anyway (dmd + druntime + 
phobos). It is quite easy to keep such development environment 
separate from system-wide dmd installation anyway.