I tried to install eric (3.4.2) (actually I think it's been renamed eric3, but the ebuild is still eric) and the install failed (see bug #558470). Yet emerge believes that the install succeeded. Reproducible: Always Steps to Reproduce: 1. 2. 3.
*** This bug has been marked as a duplicate of 55847 ***
This bug was discovered along with 558470 but is not the same. This bug is here because even though the emerge failed, the portage system thought that it didn't and marked it as installed.
You want the eric3 install script to detect a broken PyQt installation. That won't work. Ebuils can/should always rely on installed R/DEPEND stuff.