Re: Debugging Guix packages?

[Leo Famulari]

On Thu, Jan 21, 2016 at 11:21:34AM +1100, Jookia wrote:
> On Wed, Jan 20, 2016 at 11:26:14PM +0100, Ludovic Courtès wrote:
> > Yes, I agree that this would be nice.
> 
> I wonder how this could be implemented, any ideas?
> 
> > 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.

My workflow for creating patches:
$ tar xf $(guix build --source foo)
# or, if the package is in your local source tree:
$ tar xf $(./pre-inst-env guix build --source foo)
$ cd foo && git init && git add -A && git commit -m "Initial commit"
# make edits and commit them. Then:
$ git format-patch

It's not necessary to use git but it helps me keep track of my changes.

> 
> > My 2¢,
> > Ludo’.
> 
> Cheers,
> Jookia.
>