Glad to hear you're able to install on a 64 bit 12.04.
I'm having no luck with my 32 bit 12.04. I don't know where to start to solve the problem.
I installed as the example in the wiki other than I used checkinstall rather than make install. Would this cause the problem?
Checkinstall reported the installation of both cmake and sigil to be successful. Qt5 was run offline.