dsyev and dgeev not found by linker
After updating to CMake 3.16.0 (also 3.16.1), I get linker problems related to LAPACK. The problem is, CMake drops the LAPACK library and thus the linker fails.
I reported the issue, see https://gitlab.kitware.com/cmake/cmake/issues/20099
I think we have to fix the issue upstream. I currently don't see a workaround within Dune.
gruenich@kea:~/dune/complete/dune-common/build-cmake> make fmatrixtest
[100%] Built target dunecommon
[100%] Linking CXX executable fmatrixtest
/usr/bin/ld: ../../../lib/libdunecommon.a(fmatrixev.cc.o): in function `Dune::FMatrixHelp::eigenValuesLapackCall(char const*, char const*, long const*, double*, long const*, double*, double*, long const*, long*)':
/home/gruenich/dune/complete/dune-common/dune/common/fmatrixev.cc:213: undefined reference to `dsyev_'
/usr/bin/ld: ../../../lib/libdunecommon.a(fmatrixev.cc.o): in function `Dune::FMatrixHelp::eigenValuesNonsymLapackCall(char const*, char const*, long const*, double*, long const*, double*, double*, double*, long const*, double*, long const*, double*, long const*, long*)':
/home/gruenich/dune/complete/dune-common/dune/common/fmatrixev.cc:231: undefined reference to `dgeev_'
clang-9.0: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [dune/common/test/CMakeFiles/fmatrixtest.dir/build.make:90: dune/common/test/fmatrixtest] Fehler 1
make[2]: *** [CMakeFiles/Makefile2:6818: dune/common/test/CMakeFiles/fmatrixtest.dir/all] Fehler 2
make[1]: *** [CMakeFiles/Makefile2:6825: dune/common/test/CMakeFiles/fmatrixtest.dir/rule] Fehler 2
Edited by Christoph Grüninger