it can't find libhsa-runtime-ext64.so because it's not in your /opt/hsa/lib - look closely, there is ext-finalize64 and ext-image64 but no runtime-ext64. You need to (re)install HSA libs properly...
Previous versions of the HSA Runtime included hsa-runtime-ext64 library.
More recent versions don't include it anymore.
To build the example just remove -lhsa-runtime-ext64 from Makefile and run make again.
I have the latest HSA Runtime and with this change the example works
thank you for response