link error on 16.04 LTS (toolchain 2.8)

[ahoarau]

When trying to build a very simple component I get this :

CMakeFiles/fbsched.dir/fbsched.cpp.o:(.data.rel.ro._ZTV7FBSched[_ZTV7FBSched]+0x118): 
undefined reference to `RTT::TaskContext::prepareUpdateHook()'
collect2: error: ld returned 1 exit status

Same with ld or gold linker on gcc-5.

If i use clang the component builds fine but i can't import it : /home/hoarau/lwr_ws/devel/lib/orocos/gnulinux/fbsched/libfbsched-gnulinux.so: undefined symbol: _ZNK3RTT11TaskContext11getPeerListEv

[ahoarau]

I finally manage to build and load them.. maybe ccache was involved. I'll reopen if I encounter this again.