bug#27244: Should not $GUIX_LOCPATH belong to ‘glibc-locales’ rather than ‘glibc’?

[Dmitry Alexandrov]

>>>> As of now [0] a search path ‘GUIX_LOCPATH’ is exported when ‘glibc’
>>>> package, which does not comprise any locales, is installed.  I guess,
>>>> it should belong to ‘glibc-locales’ and ‘glibc-utf8-locales’ instead.
>>>
>>> The idea of search path specifications like ‘GUIX_LOCPATH’ is that the
>>> package that honors them defines them.
>>>
>>> For example, Python defines ‘PYTHONPATH’, Guile defines
>>> ‘GUILE_LOAD_PATH’, and so on.
>>
>> But locales are honoured by nearly every program.  And nearly every
>> program complains when they are not found:
>>
>> $ guix
>> guile: warning: failed to install locale
>> warning: failed to install locale: Invalid argument
>
> Yeah.
>
>>> In this case, ‘GUIX_LOCPATH’ is honored by glibc, so glibc defines it.
>>
>> From the user point of view ‘glibc’ is a package that installs
>> catchsegv(1), getconf(1), getent(1), iconv(1), ldd(1), locale(1),
>> localedef(1), makedb(1), mtrace(1), pcprofiledump, sprof(1),
>> tzselect(1) and xtrace(1).
>>
>> At least on top of a foreign distro, when Guix is used as a
>> language-specific package manager for GNU Guile for instance, that is a
>> quite unlikely a package to be installed in the profile.
>
> Right.
>
>>> If instead ‘glibc-utf8-locales’ defined it, then you’d immediately get
>>> the recommendation about setting ‘GUIX_LOCPATH’, which I guess is what
>>> you’d like to see.
>>
>> Yes, that is exactly what I expected as a user: when locales are
>> installed they come into play.
>>
>>> However, every locale-providing package would need to define it,
>>> which is not great.
>>
>> But would not thorough following “search paths are exported by the
>> active side” convention implies that every single package that ships a
>> localized program has to define $GUIX_LOCPATH?  That would be about
>> 100 % of packages, I guess.
>
> Correct.

So...?  If moving search path definitions to the packages that
actually provide searchable stuff is not feasible, another
foreign-distro-user-friendly option, I can imagine, is to have a
package (a ‘virtual package’, if you will) that would only add a
search path to etc/profile without installing any executables.

That approach might benefit to a user of Guix on top of a another
distro not only with respect to $GUIX_LOCPATH.  I hope, to be able,
for example, to read documentation of Guix-installed programs with
/usr/bin/emacs or /usr/bin/info or even /usr/bin/tkinfo rather than
emacs(1) / info(1) from Guix is a fairly reasonable wish, so having a
package that only appends $INFOPATH would be nice.  ‘emacs’ and
‘texinfo’ packages would have it as propagated dependency.

>> On the other hand, now there are only two locale-providing packages,
>> as I can see: ‘glibc-locales’ and ‘glibc-utf8-locales’.  Are there
>> plans to split them up?  Is not that supposed to be done by means of
>> ‘outputs’: glibc-locales:en, glibc-locales:fr, etc?
>
> There are no concrete plans no.  The problem is that any split is really
> arbitrary.
>
>> (By the way, ‘glibc-utf8-locales’ looks like a misnomer to me, on the
>> first glance on it a user have nothing but to think that it comprises
>> UTF-8 locales for all supported languages.)
>
> It is!  The manual clearly warns about it, saying that it’s “limited to
> a few UTF-8 locales”:
> <https://gnu.org/software/guix/manual/html_node/Application-Setup.html#Locales>.
>
> Note that the Guix 0.13.0 binary tarball comes with glibc-utf8-locales
> and glibc, such that its etc/profile defines ‘GUIX_LOCPATH’.

Excuse me?  I far as I understand, etc/profile is managed on
per-profile (i. e. per-user) basis.  Thus $GUIX_LOCPATH is not
exported until every user explicitly installs ‘glibc’ (along with all
its bin/ldd, etc).  Or did I miss something?

>>> On a related note, see this issue about indirect search path
>>> specifications: <https://bugs.gnu.org/22138>.
>>
>> Oops.  My bad, I indeed should search for opened bugs more carefully.
>> (I hope it should be possible to merge two issues within debbugs, is
>> not it?)
>
> Yes we can merge them.