regressions

[Vladimir Panteleev via Digitalmars-d]

On Friday, 30 June 2017 at 12:48:12 UTC, Martin Krejcirik wrote:
> DMD, Phobos and Druntime open regressions over time:
>
> http://bid.iline.cz/~mk/tmp/regs.png
>
> Used to be stable, but seems to be getting worse since 2016.

One thing that might have contributed to that is that until a 
year or two ago, we weren't really checking whether filed bugs 
were regressions. As it turns out, a good deal of the time when 
someone runs into a bug, they don't even realize that it's some 
behaviour that used to work previously. This is why you will 
occasionally see recently-filed bugs that are marked as 
regressions in very old versions, likely older than since the 
submitter started using D.

Knowing whether a bug is a regression is useful because then you 
can track down the change that caused it, and it's often much 
easier to find the bug in a small diff and fix it. The downside 
is that it makes the meaning of the "regression" severity less 
useful when tracking how many of those issues actually broke 
someone's code (that we know about), which is why the regressing 
version is prefixed in issue summaries.