the role and location of locale.alias

Hi,

In guix 1.4.0 there are 2 locale.alias files from glibc on the disk:

$ ls -liL --sort=size `find / -name locale.alias 2>/dev/null | grep -v X11` 940417 -r--r--r-- 1 root root 2998 Jan 1 1970 /gnu/store/0dbscs8zq4bdg8vbn9jkdgynjcn3s01p-gcc-toolchain-12.2.0/share/locale/locale.alias

940417 -r--r--r-- 1 root root 2998 Jan 1 1970 /gnu/store/5h2w4qi9hk1qzzgi1w83220ydslinr4s-glibc-2.33/share/locale/locale.alias

15716 -r--r--r-- 1 root root 2998 Jan 1 1970 /gnu/store/ayc9r7162rphy4zjw8ch01pmyh214h82-glibc-2.33/share/locale/locale.alias

15716 -r--r--r-- 1 root root 2998 Jan 1 1970 /gnu/store/c326489r6jvnl69l2nbmdvxmgzqln2hy-profile/share/locale/locale.alias

15716 -r--r--r-- 1 root root 2998 Jan 1 1970 /gnu/store/isn13ca7419sj7myb3xr3i3zbxspky8c-profile/share/locale/locale.alias

15716 -r--r--r-- 1 root root 2998 Jan 1 1970 /gnu/store/yh51nb5dq9n6pw8mrdp3nxcfmxzmrp1x-profile/share/locale/locale.alias

1058938 -r--r--r-- 1 root root 261 Jan 1 1970 /gnu/store/wf46adk80fdc1qij8472n8r2xr4cln0a-gdm-42.0/share/gdm/locale.alias

I explained the purpose of this file in

https://sourceware.org/pipermail/libc-alpha/2023-September/151524.html.

In summary, it's a configuration file whose initial contents is provided

for glibc, but which needs to be edited by the system administrator in

some situations.

For this reason, in Debian 12, the file has been moved to

/etc/locale.alias, and /usr/share/locale/locale.alias is merely

a symbolic link to /etc/locale.alias. IMO, this is the correct

way to handle this configuration file.

The way Guix handles this file provokes two problems:

1) When the system administrator wants to add a new alias, they have

to search for all occurrences of the file in the (two) glibc

installations. And if/when they install newer versions of glibc,

they will have to reapply their change again and again.

2) GNU gettext needs to access this file, in order to recognize the

same aliases that glibc recognizes. But glibc does not export the

_nl_expand_alias function. Therefore GNU gettext needs to know

where the file is. But how could GNU gettext retrieve any of the

file names

/gnu/store/5h2w4qi9hk1qzzgi1w83220ydslinr4s-glibc-2.33/share/locale/locale.alias

/gnu/store/ayc9r7162rphy4zjw8ch01pmyh214h82-glibc-2.33/share/locale/locale.alias

?

If Guix had this configuration file moved to /etc, like Debian did, GNU gettext

could be compiled with '-DLOCALE_ALIAS_PATH=\"/etc\"' and would then be able

to access it.

Bruno

Hi Bruno,

Bruno Haible <bruno@clisp.org> skribis:

[...]

Does glibc look for ‘locale.alias’ in $sysconfdir, or does it look for

it in $localstatedir?

To follow the “correct way” as you described it, glibc should look for

it in $sysconfdir by default.

That’d be impractical of course, and that’s not how Guix works

(/gnu/store is immutable).

Right now gettext in Guix ends up being compiled with:

-DLOCALE_ALIAS_PATH=\"\"

(Example build log at

https://ci.guix.gnu.org/log/0yy8zmgvc6hy1pfc41gm1bi7nhj4aqf7-gettext-0.21.)

What you propose is doable. However, how many distros provide

/etc/locale.alias? What happens when it’s missing?

We have to keep in mind that Guix can be used on top of any distro.

Thanks,

Ludo’.

Hi Ludo',

It looks for it in $(localedir), whose default value is $(datadir)/locale.

The default value of $(datadir) is $(prefix)/share.

I agree; cf. https://www.gnu.org/prep/standards/html_node/Directory-Variables.html

But it does not do so currently; therefore the distros fix up the

upstream behaviour.

In this case, localealias.c does not attempt to open a locale.alias file at all.

When it's missing, localealias.c does not open a locale.alias file.

Negative effects can be seen after the ISO 639 language code of a language

changed or after the ISO 3166 country code of a territory changed. This is

currently not relevant, but may become relevant in the future again.

Which distros have it in /etc?

- Guix 1.4.0: no

- Debian 12, Ubuntu 23.10: yes, /usr/share/locale/locale.alias is a symlink.

- CentOS Stream 9: no

- Arch 19.11: no

- openSUSE 15.5: no

- Slackware 15: no

So, to solve the problem, Guix would need to customize glibc

1. to install locale.alias in /etc (= $(sysconfdir)),

2. compile with a LOCALE_ALIAS_PATH=$(sysconfdir):$(localedir)

Then GNU gettext could be compiled with LOCALE_ALIAS_PATH=$(sysconfdir):$(localedir)

as well. This would work in standalone Guix, as well as in

Guix-on-top-of-another-distro.

Bruno