regressions

[Brad Roberts via Digitalmars-d]

On 7/2/2017 7:27 AM, Vladimir Panteleev via Digitalmars-d wrote:
> 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.

One of the biggest issues is that for a small period of time a few years 
ago, releases were actually gated on fixing regressions.  That stopped 
at some point and the backslide has gotten pretty bad. There was a 
period where there was exactly one open regression. It's one of my big 
disappointments in the current dev/release cycles.  That said, since I 
really haven't been participating in active development, I tend to just 
bite my tongue and say nothing. Holding to a line of no known 
regressions is a critical aspect of incrementally better releases.