It seems that ubuntuone-client-data during the test-rebuild [1] in wily fails to build from source on amd64 due to some PEP8 errors on package build. Log:
make[1]: Entering directory '/«PKGBUILDDIR»'
./run-tests
+ python ./setup.py build clean
running build
running build_i18n
intltool-update -p -g ubuntuone-client-data
running build_icons
running build_help
running clean
WARNING: the following files are not recognized by DistUtilsExtra.auto:
PKG-INFO
po/LINGUAS
run-tests
ubuntuone-icons.svg
ubuntuone.icns
ubuntuone.ico
++ which python3
+ '[' -x /usr/bin/python3 ']'
+ python3 ./setup.py build clean
running build
running clean
+ pyflakes setup.py
+ pep8 --repeat --exclude=.pc . setup.py
./setup.py:45:1: E402 module level import not at top of file
./setup.py:46:1: E402 module level import not at top of file
setup.py:45:1: E402 module level import not at top of file
setup.py:46:1: E402 module level import not at top of file
debian/rules:7: recipe for target 'override_dh_auto_test' failed
make[1]: *** [override_dh_auto_test] Error 1
make[1]: Leaving directory '/«PKGBUILDDIR»'
make: *** [build] Error 2
debian/rules:4: recipe for target 'build' failed
dpkg-buildpackage: error: debian/rules build gave error exit status 2
[1] http://people.ubuntuwire.org/~wgrant/rebuild-ftbfs-test/test-rebuild-20151001-wily.html
Here's a debdiff with the fix for the issue.