Disable the optional flexblas support as system flexiblas is possibly used as flexiblas is not a depends and the entire build chain to support using flexibls is not setup. As this does not seem to be needed with the spack blas and lapack, it is easier to disable (#47514)

var/spack/repos/builtin/packages/armadillo/package.py

@@ -87,4 +87,9 @@ def cmake_args(self):
             self.define("SuperLU_LIBRARY", spec["superlu"].libs.joined(";")),
             # HDF5 support
             self.define("DETECT_HDF5", "ON" if spec.satisfies("+hdf5") else "OFF"),
+            # disable flexiblas support because armadillo will possibly detect system
+            # flexiblas which causes problems. If this is removed, then SuperLU and ARPACK must
+            # also link with Flexiblas. As this does not seem to be needed with the spack
+            # blas and lapack, it is easier to disable
+            self.define("ALLOW_FLEXIBLAS_LINUX", "OFF"),
         ]