| The LAPACK compatibility library is enabled with `EIGEN_BUILD_LAPACK` and | |
| requires `EIGEN_BUILD_BLAS`. Its optional numerical tests | |
| (`EIGEN_ENABLE_LAPACK_TESTS`) require a Fortran compiler and the LAPACK test data. | |
| The tests and their summary run through CMake/CTest without Python. | |
| `LAPACK_Test_Summary` waits for the registered numerical tests and combines | |
| only their expected output files into `TESTING/testing_results.txt` in the | |
| LAPACK build directory. It fails when the output reports numerical errors, | |
| illegal-argument or INFO diagnostics, when an expected output is missing, or | |
| when no numerical tests were analyzed. Selecting `LAPACK_Test_Summary` alone also | |
| runs its numerical tests through a CTest fixture. If a numerical driver fails to | |
| execute successfully, CTest skips the summary. | |
| Balancing tests contribute their example counts and fail on nonzero INFO/ILO | |
| error counts or non-finite maximum errors. Their finite maximum errors remain | |
| in the combined report; these drivers do not specify a pass/fail threshold. | |
| The numerical tests use unmodified LAPACK 3.12.1 sources, downloaded with a pinned | |
| SHA-256 hash. They exercise Eigen's BLAS/LAPACK implementations, using reference | |
| LAPACK for the remaining routines. All test cases remain enabled; known numerical | |
| and test-driver failures are reported by the summary. |