Without this, GCC 12 issues the following warning:
/__w/Kratos/Kratos/external_libraries/amgcl/adapter/block_matrix.hpp:84:44: error: member 'amgcl::adapter::block_matrix_adapter<amgcl::backend::crs<float, long int, long int>, amgcl::static_matrix<float, 3, 3> >::row_iterator::buf' is used uninitialized [-Werror=uninitialized]
Without this, GCC 12 issues the following warning: