Sorry for being late to this discussion, but there are a few points
and a suggestion I'd like to make:
1. Reproducibility is not a big concern
Quoting policy:
Packages should build reproducibly, which for the purposes of this
document means that given
...
- a set of environment variable values;
...
repeatedly building the source package
...
with ... exactly those environment variable values set
will produce bit-for-bit identical binary packages.
There is also the practical side that our buildds already set LC_ALL=C.UTF-8,
in main one can already assume that every package in a release has been
built with in this environment.
2. RC is what does FTBFS on the buildds
Usually a FTBFS is RC only when it happens on the buildds.
FTBFS with non-C.UTF-8 locales itself is not RC,
just like FTBFS on single-core machines is not RC.
These are of course still bugs, especially if a different UTF-8 locale
results in test failures that indicate runtime issues.
3. Importance of build-time diversity
Less than 3 years ago, having build-arch/build-indep targets in
debian/rules was a usecase important enought for some people that a MBF
with hundreds of RC bugs was done and many people (including myself)
spent time fixing this usecase by adding build-arch/build-indep targets
to packages.
Calling the clean target manually is something I frequently do.
Doing a build test or autopkgtest with an Estonian or Turkish locale
is hard/impossible when something (no matter whether debian/rules or
debhelper or dpkg-buildpackage) enforces C.UTF-8.
4. C.UTF-8 or *some* UTF-8 locale?
The main problems are with non-UTF-8 locales, it might be
uncontroversial to declare building with a non-UTF-8 locale
unsupported and make dpkg-buildpackage reject this with a message like:
Building with a non-UTF-8 locale is no longer supported, please do
LC_ALL=C.UTF-8 dpkg-buildpackage
This should be sufficient to address the root cause of all/most of the
current manual and tooling settings of C.UTF-8, and could actually
enable useful testbuilds for finding problems for Turkish users.
cu
Adrian
