dpkg-buildpackage test suite failure

[Sven Joachim <svenjoac@gmx.de>]

I'm getting the following error when running the test suite:

,----
| dpkg_buildpackage.t: error: /usr/local/src/dpkg/build-tree/scripts/../../scripts/dpkg-buildpackage.pl --host-arch=amd64 --build=source --check-command= gave error exit status 25
| # Looks like your test exited with 25 before it could output anything.
| ../../scripts/t/dpkg_buildpackage.t ........ 
| Dubious, test returned 25 (wstat 6400, 0x1900)
| Failed 7/7 subtests 
`----

After redirecting dpkg-buildpackage's error messages to a real file
instead of /dev/null in the test_build function the problem seems to be
clear:

,----
| dpkg-architecture: warning: specified GNU system type x86_64-linux-gnu does not match CC system type i686-linux-gnu, try setting a correct CC environment variable
|  dpkg-source --before-build test-source-0
|  fakeroot debian/rules clean
|  dpkg-source -b test-source-0
| dpkg-source: warning: missing information for output field Standards-Version
|  dpkg-genchanges --build=source >../test-source_0_source.changes
| dpkg-genchanges: info: including full source code in upload
|  dpkg-source --after-build test-source-0
|  signfile test-source_0.dsc
| gpg: skipped "Dpkg Developers <debian-dpkg@lists.debian.org>": No secret key
| gpg: dpkg-sign.dsbr2X3M/test-source_0.dsc: clearsign failed: No secret key
| dpkg-buildpackage.pl: error: failed to sign .dsc and .changes file
`----

Cheers,
       Sven