Comment 30 for bug 719446

Kernel compilation produces a lot of warnings and it's ok, as long as it gives you a 'final product' in the form of .deb packages. Errors (as opposed to warnings) will stop the compilation and not produce a .deb package.

To remove packages installed via build dep, you can use this helpful tip:
http://www.webupd8.org/2010/10/undo-apt-get-build-dep-remove-build.html