[Nix-dev] How do you like the verbosity when building?

[Nicolas Pierron]

Hi Marc,

On Thu, Jul 17, 2008 at 19:39, Marc Weber <marco-oweber at gmx.de> wrote:
> Sometimes I appreciate seeing what happens.. On the other hand if you're
> using -j2 option or such you'll get a mixture which is hard to read.

I agree, multiple compilation lines at the same time is hard to read.

> Would you prefer something like
>
> starting build /nix/store/XXXXX.drv, log file is /nix/var/nix/log/drvs/XXXXX.drv.log
> .......
> done XXXXX

This sounds good for an automatic log extraction.

> So if you mix up multiple builds you'll get
>
> starting build /nix/store/YXXXX.drv (1/2), log file is /nix/var/nix/log/drvs/YXXXX.drv.log
> +++
> starting build /nix/store/XXXXX.drv (2/2), log file is /nix/var/nix/log/drvs/XXXXX.drv.log
> .+...+.
> done XXXXX (1/2)
> +++++++++++
> done YXXXX (2/2)
>
> (each . / +  corresponds to one log line so that you see immediately that a build
> process has stopped)

I admit that we have to mix the log on the output screen otherwise we
will have some question like "why the -j option is not working". On
the other hand I would prefer to give one number per package which can
be used to prefix each line of the build job and use global build
status only at the end of each job with a percent notation or a ration
notation.  With these format the extraction of each build log would be
easier.


starting build /nix/store/YYYYY.drv (1), log file is
/nix/var/nix/log/drvs/YXXXX.drv.log
1: ...
1: ...
starting build /nix/store/XXXXX.drv (2), log file is
/nix/var/nix/log/drvs/XXXXX.drv.log
1: ...
2: ...
2: ...
1: ...
2: ...
done XXXXX (2) [50%]
1: ...
1: ...
done YYYYY (1) [100%]

> Of course you want to see the log especially if it fail. Then the whole
> log (or maybe only the last 100 lines) could be printed..

I do not think this is a good idea.  I know project that are on the
Delft build-farm where the last 100 lines are irrelevant. I prefer the
idea of being able to extract log.

-- 
Nicolas Pierron
- If you are doing something twice then you should try to do it once.