Re: Debugging Guix packages?

[Ben Woodcroft]

Hi there,

On 21/01/16 10:21, Jookia wrote:
> On Wed, Jan 20, 2016 at 11:26:14PM +0100, Ludovic Courtès wrote:
> > OTOH, for things like GCC, once you start fiddling with the build tree,
> > you quickly lose track of what state you’re in.
> >
> > My workflow has been:
> >
> >    guix build foo -K
> >    # build fails
> >    cd /tmp/guix-build*
> >    source environment-variables
> >    # Fiddle with the build tree to get additional info about the problem
> >    # and a possible fix.
> >    # Write a phase that hopefully fixes the issue.
> >    # Try again.
> >
> > Since the ‘environment-variables’ file always contains the value of
> > environment variables at the time where the build failed (rather than
> > their initial value), it usually works quite well.
> This could be good enough for now but again this doesn't work with this like
> builds that don't fail. My concrete example is wanting to patch software but not
> knowing how to get to the pre-patch state so I can then work from that in
> testing which patches apply and which don't, or make my own.
Can I ask, why Ricardo's suggestion does not address this concern? This 
approach makes builds fail, so then you can inspect. I often use this.

My 2c here, would it be possible to echo any system* commands used in 
the build to the log? This would help make things concrete and put flags 
in the build log sand.

Thanks,
ben