DMD needs branches

[Brad Roberts]

Russell Lewis wrote:
> Brad Roberts wrote:
>> On Fri, 13 Apr 2007, Walter Bright wrote:
>>> But bugfixes themselves can cause such problems.
>>
>> Sure, they can.  That's not the issue.  The issue is that a bug fix is 
>> considerably less likely to introduce regressions than new features 
>> are.  By separating where new features are emerging, you've got a much 
>> higher chance of keeping a monotomically increasing in stability 
>> release version.
> 
> Let me say something here about "monotonically increasing stability." 
> IMHO, this is not an absolute requirement of a "stable" release.  At 
> least in my company, we don't pick up new tools (compilers, etc.) 
> without putting in some test on them.  If I was using dmd for work, for 
> instance, I wouldn't put a new version of the compiler to production use 
> until (at least) the new DStress report had come out, and I had done a 
> test build with the compiler on my code.  (Plus run a few quick 
> regression tests on my code built with the new compiler.)  So if there 
> are new bugs in a new compiler, I simply never pick it up.  That's 
> unfortunate, but not terminal.
> 
> I know that some here will disagree, but to me the essence of a "stable" 
> branch is not bug-free compilers every time, but instead a reasonable 
> expectation that I will eventually get my bugs fixed without having to 
> simultaneously pick up new language changes.

Of course it's not an absolute requirement.  Achieving it would require 
a perfect test suite which by necessity would mean that there's no bugs. 
  I purposely said 'much higher chance of keeping a...' to indicate 
that's the goal of release branch.