A user had trouble making a 64 bit version of wgrib2 with the Leopard OS. Some of the libraries where 32 and other 64 bits. To get everything to work, he had to get the "-m64" flag to all the compiles. He did this by setting the following environment variables before doing the "gmake -f makefile" export CC=/usr/bin/gcc export CXX=/usr/bin/c++ export F77=ifort export CFLAGS="-O2 -m64" export CXXFLAGS="-O2 -m64" export FFLAGS="-O2 -m64" Another user had to the above and change makefile wCPPFLAGS=-O2 to wCPPFLAGS=-O2 -m64 ------------------------------------------------- Another user Mac user had 32-bit MySQL libraries and had to remove the -m64 (2/2010)