We had a user build failing, and when we dug into it, it turned out that mkl_link_tool was failing to load:
.../mkl_link_tool: error while loading shared libraries: libstdc++.so.6: wrong ELF class: ELFCLASS64
This happened with 2018.3, 2019.0, and 2019.5, so guessing it's just a 32-bit app that Intel distributes. Is the expectation that everyone will still have 32-bit libraries installed at this late date? We don't even have 32-bit libstdc++ installed in our base image any more. Is there a 64-bit mkl_link_tool around somewhere?