Thanks for the help I got. As blas/lapack is fortran stuff, it needs to be compiled with a fortran comiler. Using the following is successful:
AC_LANG(Fortran 77) AC_CHECK_LIB(blas,ddot) AC_CHECK_LIB(lapack,sspsv) Which seems the cleanest thing to do IMO. A remaining question though: why does not 'ldd libblas.so' show libg2c and libm? /Micce -- Mikael Hedin, MSc +46 (0)8 344979 (home) +46 (0)70 5891533 (mobile) [gpg key fingerprint = 387F A8DB DC2A 50E3 FE26 30C4 5793 29D3 C01B 2A22]