Add an option to hide output before a certain timeout is reached

[WaffleLapkin]

I'm writing a program which (among other things) executes nix-build to build a components that needs to be run afterwards. I would like to show users that this program isn't stuck and is just building the component using nom.

This works quite nicely, however, this also always adds a line like Finished at 02:31:03 after 1s to the output. Which is somewhat annoying/confusing for cases when the component build is in the cache and everything finishes in <1s.

I might be able to hack this around on my end, but ideally I want to just set some argument or an environment variable (say NIX_OUTPUT_MONITOR_HIDE_BEFORE=5) which would stop nom from showing output before a certain timeout has passed.

Is this viable? What do you think?

[maralorn]

This is absolutely viable and that feature actually exists. Wenn you use nom shell, nom will cleanup after itself. Only problem is, that this internal config option is not exposed via a flag.

[maralorn]

Thinking about it we can even do this more granularly. e.g. only clear the screen when nothing was build or when the build took less than 5s or something like that.

[WaffleLapkin]

@maralorn that sounds great!

Do you think you'll have time and will to implement it anytime soon?

Otherwise, do you have ideas of how this could be implemented / pointers of where to look? I'm far from being well versed in haskell but I could at least try 😅

[maralorn]

The problem is that we currently have no proper method of configuration. I would like to have one but there should be a bit of thought in that. Generally I really want to work on this but I can’t currently make promises on when I can get to it.

Besides that this is really easy. Currently there is a boolean called silent in the Config type in Main.hs and you just need to set it to True somehow.