Bad behaviour prior to this commit:

1. The package is broken: pango
2. Package sdl_pango depends on broken pango
3. When t4k_common (which depends on sdl_pango) is built,
    pango is tried to build again.

This issue was caused by the error fixed in this commit:
if a package A depends on a broken package B,
then the package A is also BROKEN.
So if a package C depends on package A, then all of them
are broken:

(*)B <- A <- C

B is not "rebuilt" for C.