Have installed Qt 5.4.2 on Ubuntu 15.04 x64 with QIF - when debugging, most of the symbols are not loaded, starting with the simpliest QSettings.

The info shared command gives:

61info shared

&"info shared\n"
~"From To Syms Read Shared Object Library\n"
~"0x00007f0098eb8aa0 0x00007f0098ed4590 Yes /lib64/ld-linux-x86-64.so.2\n"
~"0x00007f0098b86580 0x00007f0098c74458 Yes /opt/Qt/5.4/gcc_64/lib/libQt5Network.so.5\n"
~"0x00007f009848e5e0 0x00007f009879dad8 Yes /opt/Qt/5.4/gcc_64/lib/libQt5Core.so.5\n"
~"0x00007f009815f9a0 0x00007f00981cc5af Yes /usr/lib/x86_64-linux-gnu/libstdc++.so.6\n"
~"0x00007f0097ef0ab0 0x00007f0097f00805 Yes /lib/x86_64-linux-gnu/libgcc_s.so.1\n"
~"0x00007f0097b434f0 0x00007f0097c96354 Yes /lib/x86_64-linux-gnu/libc.so.6\n"
~"0x00007f009790ba90 0x00007f0097918c41 Yes /lib/x86_64-linux-gnu/libpthread.so.0\n"
~"0x00007f0097569970 0x00007f009769f5a8 Yes /opt/Qt/5.4/gcc_64/lib/libicui18n.so.53\n"
~"0x00007f0097183d50 0x00007f0097248f88 Yes /opt/Qt/5.4/gcc_64/lib/libicuuc.so.53\n"
~"0x00007f0096f2be60 0x00007f0096f2ca5e Yes /lib/x86_64-linux-gnu/libdl.so.2\n"
~"0x00007f0096d296c0 0x00007f0096d2983a Yes /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0\n"
~"0x00007f0096b23190 0x00007f0096b26167 Yes /lib/x86_64-linux-gnu/librt.so.1\n"
~"0x00007f009682c690 0x00007f00968a3529 Yes /lib/x86_64-linux-gnu/libglib-2.0.so.0\n"
~"0x00007f009650f5a0 0x00007f0096580c61 Yes /lib/x86_64-linux-gnu/libm.so.6\n"
~" Yes /opt/Qt/5.4/gcc_64/lib/libicudata.so.53\n"
~"0x00007f0094c16600 0x00007f0094c64fb5 Yes /lib/x86_64-linux-gnu/libpcre.so.3\n"
61^done

On the same machine have installed Qt 5.4.1 with Qt Creator 3.1.1 from the official Ubuntu repo - everything's OK - all the symbols are loaded. The info shared shows a slightly different set of libraries:

29info shared

&"info shared\n"
~"From To Syms Read Shared Object Library\n"
~"0x00007f214f533aa0 0x00007f214f54f590 Yes /lib64/ld-linux-x86-64.so.2\n"
~"0x00007f214f628c40 0x00007f214f708dea Yes /usr/lib/x86_64-linux-gnu/libQt5Network.so.5\n"
~"0x00007f214f06a290 0x00007f214f384182 Yes /usr/lib/x86_64-linux-gnu/libQt5Core.so.5\n"
~"0x00007f214ed3c9a0 0x00007f214eda95af Yes /usr/lib/x86_64-linux-gnu/libstdc++.so.6\n"
~"0x00007f214eacdab0 0x00007f214eadd805 Yes /lib/x86_64-linux-gnu/libgcc_s.so.1\n"
~"0x00007f214e7204f0 0x00007f214e873354 Yes /lib/x86_64-linux-gnu/libc.so.6\n"
~"0x00007f214e4e8a90 0x00007f214e4f5c41 Yes /lib/x86_64-linux-gnu/libpthread.so.0\n"
~"0x00007f214e2c9df0 0x00007f214e2db029 Yes /lib/x86_64-linux-gnu/libz.so.1\n"
~"0x00007f214df50750 0x00007f214e0639c5 Yes /usr/lib/x86_64-linux-gnu/libicui18n.so.52\n"
~"0x00007f214db8a6f0 0x00007f214dc3e808 Yes /usr/lib/x86_64-linux-gnu/libicuuc.so.52\n"
~"0x00007f214d934e60 0x00007f214d935a5e Yes /lib/x86_64-linux-gnu/libdl.so.2\n"
~"0x00007f214d63f690 0x00007f214d6b6529 Yes /lib/x86_64-linux-gnu/libglib-2.0.so.0\n"
~"0x00007f214d41f190 0x00007f214d422167 Yes /lib/x86_64-linux-gnu/librt.so.1\n"
~"0x00007f214d11a5a0 0x00007f214d18bc61 Yes /lib/x86_64-linux-gnu/libm.so.6\n"
~"0x00007f214b8a8570 0x00007f214b8a8670 Yes /usr/lib/x86_64-linux-gnu/libicudata.so.52\n"
~"0x00007f214b63c600 0x00007f214b68afb5 Yes /lib/x86_64-linux-gnu/libpcre.so.3\n"
29^done

I have tried to use Source PAth Mapping to substitute /var/tmp/qt-src with /opt/Qt/5.4/gcc_64/include or with /opt/Qt/5.4/gcc_64, but no luck.

Anybody could tell, please, what's to be done to make it work?