Marius Bakke <mbakke@fastmail.com> writes:

> Pierre Neidhardt <ambrevar@gmail.com> writes:
>
>>> guix package -I local
>> glibc-utf8-locales	2.26.105-g0890d5379c	out	/gnu/store/3k6hl20c3b7big8ngrsl6mj9k8xav99d-glibc-utf8-locales-2.26.105-g0890d5379c
>>
>>> guix package -I emacs
>> emacs	25.3	out	/gnu/store/y335nx4r08m6kg0yrna7spfwr4s05n36-emacs-25.3
>>
>> How do I check which glibc Emacs is using?
>> I can think of `ldd emacs` but... Where is ldd? :p
>
> "ldd" is in "glibc" :-)
>
> You can also use `guix gc -R /gnu/store/...-emacs-25.3 | grep glibc`.

Here:

	> guix gc -R ${guix build emacs} | grep glibc
	/gnu/store/4sqaib7c2dfjv62ivrg9b8wa7bh226la-glibc-2.26.105-g0890d5379c

>> A more general question: How do I find to which non-installed package a
>> filename belongs?
>
> Guix does not currently know anything about the files inside each
> package, I typically do a web search...

This is too bad, I believe it's an important feature for any package
manager.
As far as I can tell, `portage` and `pacman` can both do it.

Any plan regarding guix?

>> If Emacs happens to be using glibc 2.25, how could such a sitution occur
>> in the first place?  Why is glibc 2.25 needed at all?
>
> This situation can occur when you've installed emacs built against glibc
> 2.25 (which was the glibc in Guix until ~February), and then later
> updated "glibc-utf8-locales" to 2.26 which has incompatible locale data.
>
> Updating emacs would fix it in that case, since it would be built
> against the new glibc.

Running `guix package -u emacs` does nothing special, possibly because
it's already up to date.  Can I force a rebuild?

-- 
Pierre Neidhardt