n00n, tnx, but problem was with PA runtime ;)
after second start via steam all looks ok about libstdc++.so.6, looks like radeonsi in debian builded with libstdc++.so >= 3.0.20 version, runtime...
replaced libstdc++.so.6 to system version and it started, with some resolution problems %)
yes, i have only TITANS installed from steam with LIBGL_DEBUG=verbose ./PA --coherent-log-level=TRACE --gl-debug --software-ui i got:...
Debian stretch(testing), radeonsi drivers, OpenGL version string: 3.0 Mesa 10.6.3 [14:30:53.922] INFO Started at 2015-08-24 14:30:53...
Separate names with a comma.