bug#22970: guix edit mutt -- not working

[Jean Louis <guix@rcdrun.com>]

Hello Alex,

I have followed your recommendation, and mutt is working modified.
However, now I get useless error messages. And I can imagine, if I have
modified 10 packages, that I would get 10x that much of error messages.

warning: collision encountered:
/gnu/store/xxzgai9khdfhk70p06vs6akrarzph9r2-my-mutt-1.5.24/share/man/man1/mutt.1.gz
/gnu/store/vh7ghk1xlrn4crshqrdygp5573aipk44-mutt-1.5.24/share/man/man1/mutt.1.gz 

warning: arbitrarily choosing
/gnu/store/xxzgai9khdfhk70p06vs6akrarzph9r2-my-mutt-1.5.24/share/man/man5/muttrc.5.gz

warning: collision encountered:
/gnu/store/xxzgai9khdfhk70p06vs6akrarzph9r2-my-mutt-1.5.24/bin/mutt
/gnu/store/vh7ghk1xlrn4crshqrdygp5573aipk44-mutt-1.5.24/bin/mutt 

warning: arbitrarily choosing
/gnu/store/xxzgai9khdfhk70p06vs6akrarzph9r2-my-mutt-1.5.24/bin/mutt

warning: collision encountered:
/gnu/store/xxzgai9khdfhk70p06vs6akrarzph9r2-my-mutt-1.5.24/bin/flea
/gnu/store/vh7ghk1xlrn4crshqrdygp5573aipk44-mutt-1.5.24/bin/flea 

Let me stop with copy and paste, because there are many more lines like
that.

Maybe it is design of guix package manager, maybe it is my fault. 

I understood that I can change definitions for guix packages, and such
would be installed. There shall be no warnings like this.

I do intend to make about 5-10 packages for system I use, and I worry
about future warning messages, it will be like 3-4 screens, making guix
package manager not user-friendly. I would not see real errors.

On Fri, Mar 11, 2016 at 01:48:39PM +0300, Alex Kost wrote:
> Jean Louis (2016-03-10 22:34 +0300) wrote:
> 
> > Hello Andreas,
> >
> > I have now 2 files in gnu/guix/packages/*.scm, for mutt and postgresql:
> > and now I get each time on running guix, following:
> >
> > guix package: warning: failed to load '(databases)':
> > ERROR: no code for module (databases)
> > guix package: warning: failed to load '(mutt)':
> > ERROR: no code for module (mutt)
> >
> > because 2 files are: databases.scm and mutt.scm
> >
> > I have already installed mutt, with changes, and it works. On the end of
> > file there is word "mutt". Similar for PostgreSQL, only it did not yet
> > compile.
> >
> > Now I get a feeling, if I have 20 files to change or adapt to my system,
> > I will get 20 warnings by each run of guix package manager.
> >
> > Somehow it does not feel right.
> >
> > It would be more logical to have GUIX_PACKAGE_PATH plus one separate
> > file where some modified or user related packages are listed, instead of
> > having the package name on the end of *.scm file.
> 
> I agree, using GUIX_PACKAGE_PATH is such a nice way to keep your own
> packages.  I don't understand why Andreas recommended to use "guix
> package -f".  I think it is suitable to build some development
> "guix.scm" file (not related, but see ¹).  But for user packages, I
> think keeping them in GUIX_PACKAGE_PATH directories is a much better
> solution.
> 
> I also don't recommend to use the same /gnu/packages/*.scm structure, as
> there may be problems with this.  For example, you copied
> /gnu/packages/databases.scm to your GUIX_PACKAGE_PATH dir and modified
> some package in it.  Then you have to follow the changes in this file
> made in Guix, and update your local databases.scm accordingly all the
> time.
> 
> So if you want to keep all your packages in a single file, you can make
> "<some-dir>/my-guix-packages.scm", add <some-dir> to GUIX_PACKAGE_PATH,
> and that's it!  This "my-guix-packages.scm" file will look like this:
> 

> (define-module (my-guix-packages)
>   #:use-module (guix packages)
>   #:use-module (guix download)
>   #:use-module (guix utils)
>   #:use-module (gnu packages mail))
> 
> (define-public my-mutt
>   (package
>     (inherit mutt)
>     (name "my-mutt")
>     (arguments
>      (substitute-keyword-arguments (package-arguments mutt)
>        ((#:configure-flags cf)
>         `(cons "--enable-hcache" ,cf))))
>     (synopsis (string-append (package-synopsis mutt)
>                              " (configured with --enable-hcache)"))))

> 
> And all guix commands will find packages in this file, for example you
> can do: "guix package -i my-mutt".  Try it!