Re: meson: Make test output much more useful on failure (both in CI and locally)

On Tue, 7 Apr 2026 at 15:15, Peter Eisentraut <peter(at)eisentraut(dot)org> wrote:
> I could see this maybe being useful if the entire diff file is, say,
> less than 50 lines. But I don't see how seeing a truncated diff by
> default can be useful.

The idea behind that is that if it's a big diff it's often because the
server crashed. And the top of the diff will then tell you which query
crashed the server. Similarly if some important command like CREATE
TABLE failed, the diff after that is also useless.

Are you saying that 80 diff lines are too many? And to limit it to 40
or 50 instead by default. Could you try changing the number locally
and if that would address the annoyance? Or would it only be solved by
having no diff output at all? And would being able to configure the
amount of lines using a env variable help?

> The commit message makes reference to "especially on CI". Maybe this
> new behavior should be triggered by being on CI, or the output not being
> a terminal, or something like that.

I definitely want the diff in my terminal too, when testing locally.
There are far too many regression.diffs file in my build directory.