/etc/grml/fai/config/scripts/GRMLBASE/25-locales

The meaning of class LOCALES has changed now. Therefore you cannot build
a live-cd with minimal locales support anymore :-(

I suggest two possible solutions:

1. Introduce another class MINLOCALES which could be used to build minimal
locales support (from /etc/locale.gen.minimal) in contrast to class
LOCALES which could be used for full locales support (from /etc/locale.gen.grml).
Without LOCALES or MINLOCALES all locales files should be deleted.

2. Another solution providing more flexible control of locales settings would
be to not rely on classes and /etc/locale.gen.* template files but rather use
a new variable LOCALES in /etc/grml/fai/config/class/GRMLBASE.var. This could
be evaluated in the script 25-locales to create the files /etc/locale.gen
and /etc/locale.nopurge. The LOCALES variable could be a comma separated list
of items. Valid items might be full locale specifications (e.g. "en_US ISO-8859-1")
or language codes (e.g. "de_DE") or the special item "all". Any given language
code must be translated to all the locales found in /usr/share/i18n/SUPPORTED.
The special item "all" would expand to all locales available.
To get the default behaviour for the new grml live-cd you would set LOCALES=""
(or use another special item "none" to make it very clear to the user). For the
old minimal locales support you would set LOCALES="de_AT,de_CH,de_DE,en_GB,en_US".

I believe the second solution is much more user friendly and should be
prefered, even if it requires bit more code changes.

Bugreport and ideas by Thomas Lehmann, thanks!