Tests using R-devel on x86_64 Fedora 34 Linux with alternative BLAS/LAPACK implementations. Except as noted below, R was configured as per https://www.stats.ox.ac.uk/pub/bdr/Rconfig/r-devel-linux-x86_64-fedora-gcc ATLAS: Serial ATLAS using the Fedora shared libraries. (Currently version 3.10.3.) libRblas.so was replaced by a symlink to /usr/lib64/atlas/libsatlas.so . It reports using LAPACK 3.10.0. MKL: Intel MKL '2023.2.0' used to build Rblas and also provides LAPACK (which is version 3.10.1). R was configured by (csh script) setenv MKL_LIB_PATH /usr/local/MKL/mkl/lib/intel64 setenv LD_LIBRARY_PATH $MKL_LIB_PATH setenv MKL "-L$MKL_LIB_PATH -lmkl_gf_lp64 -lmkl_core -lmkl_sequential" ~/R/svn/R-devel/configure -C --with-blas="$MKL" --with-lapack --enable-lto=R OpenBLAS: Serial OpenBLAS using the Fedora shared libraries (currently version 0.3.19). libRblas.so was replaced by a symlink to /usr/lib64/libopenblas.so (part of openblas-devel, linked from openblas-serial). This reports using LAPACK 3.9.0. Pto tem, using setenv _R_CHECK_MBCS_CONVERSION_FAILURE_ true