The CMake compiler detection for Clang 17 and 18 as CUDA compiler failed, because CMake tries to compile an empty CUDA source code file with the default c++ standard of the compiler, which is gnu++17. Because CUDA does not support float 128 (gnu extension) the compilation and the compiler detection fails.
The CMake compiler detection for Clang 17 and 18 as CUDA compiler failed, because CMake tries to compile an empty CUDA source code file with the default c++ standard of the compiler, which is
gnu++17. Because CUDA does not support float 128 (gnu extension) the compilation and the compiler detection fails.This patch temporary set the default c++ standard to
c++17. For more details, see here: https://gitlab.kitware.com/cmake/cmake/-/issues/25861Our CI cannot test the fix because the Debian developers patches the
libstdc++to handle the 128 bit problem.I tested it locally on the workstation with Clang 16, 17 and 18. The
libstdc++is installed viaspack. Therefore the Debian patch is missing.In Clang 19, the bug is fixed: https://github.com/llvm/llvm-project/issues/88695
fixed: #2254