Bug#27777: dpkg-buildpackage don't work with LANG set

[Torsten Hilbrich <Torsten.Hilbrich@gmx.net>]

Package: dpkg-dev
Version: 1.4.0.30

If I call dpkg-buildpackage with LANG set to something else than C or
POSIX I get the following error message:

~/tmp/wwwoffle-2.0$ LANG=de_DE dpkg-buildpackage

parsechangelog/debian: error: unable to open substvars file debian/substvars: Datei oder Verzeichnis nicht gefunden
dpkg-buildpackage: unable to determine source package

(The error message means: File or directory not found).

If I use an english locale or set LANG to C or POSIX it works as expected:

~/tmp/wwwoffle-2.0$ LANG=C dpkg-buildpackage

dpkg-buildpackage: source package is wwwoffle
dpkg-buildpackage: source version is 2.0-1
[...]

I tried all the locale specific variables and it seems that the
LC_MESSAGES setting is to blame, e.g.

	LC_MESSAGE=de_DE dpkg-buildpackage

yields the same error message.

I found the following part around line 89 in /usr/lib/dpkg/controllib.pl:

        } elsif ($! !~ m/no such file or directory/i) {
            &error("unable to open substvars file $varlistfile: $!");
        }

The reason for the problem is obvious, with the above setting the
error message is not the expected one.

Maybe you should set LC_MESSAGES inside this script to POSIX to get
the correct error message.  Unfortunately, I don't know the Perl way
for doing it, but a 

$ENV{'LC_MESSAGES'}='POSIX';

at the begin of controllib.pl was sufficient.

	Torsten