When the closest related parent to PORTAGE_TMPDIR and a file a mythtv or a related plugin tries to install is not '/', qmake will 'helpfully' fix the path into a relative one. With a PORTAGE_TMPDIR of /var/foo and an all files installed are in /usr, there is no problem, but if PORTAGE_TMPDIR is /usr/tmp (say for disk space limitations), qmake will generate rules like the following: -$(INSTALL_FILE) "$(TARGET)" "$(INSTALL_ROOT)../../../../../../../../lib/$(TARGET)" which causes sandbox violations in /lib and /bin. Digging through the qt3 eclass, I found it passes "CONFIG += no_fixpath" to qmake. Bug 120116 mentioned it's used to fix situations like this, and I confirmed it worked on a simple example qmake project. Hopefully adding "CONFIG += no_fixpath" to qmake calls in the mythtv ebuilds and the mythtv-plugin eclass will fix these build problems, but I won't know for sure for a few hours.
Adding "CONFIG += no_fixpath" to the qmake command fixed my sandbox build-problems. It's needed in eclass/mythtv-plugin.eclass, media-tv/mythtv/*.ebuild, and x11-themes/mythtv-themes/*.ebuild
Actually, it looks like they finally implemented eqmake3 like I had requested. Try that.
