10:36 AM <xnox> cjwatson, superm1 - ok found it. Mythtv plugins are funky and did tricks behind our back with iterating:
10:36 AM <xnox> if [ x"$qmake" = "xqmake" ]; then
10:36 AM <xnox>     CHECK_QMAKE="qmake-qt5 /usr/lib64/qt5/bin/qmake /usr/lib/x86_64-linux-gnu/qt5/bin/qmake /usr/lib/i386-linux-gnu/qt5/bin/qmake /usr/lib/arm-linux-gnueabihf/qt5/bin/qmake /usr/local/lib/qt5/bin/qmake $\
10:36 AM <xnox> qmake qmake-qt4"
10:36 AM <xnox> in case of "qmake" default qmake specified.
10:37 AM <xnox> and thus it "worked" on x86_64, i386, armhf only =)
10:37 AM <xnox> exporting QT_SELECT=5 would have been a better trick.
10:37 AM <xnox> or like querying the triplet from gcc.