On 07/12/10 04:31, Dr. David Kirkby wrote: > I know the following method works in some cases > > export CLFAGS=-m64 > export LDFLAGS=-m64 > ./configure > > other times (e.g. Python, Singular), one needs to define CC to be "gcc > -m64". Normally "configure" just uses the first compiler in your path, preferring gcc to cc if it works. If you want to use a compiler in a non-default configuration (say, 64-bit), you need to tell "configure" about it with something like this: configure CC='gcc -m64 -L/usr/local/lib64 -R/usr/local/lib64' using whatever options are needed on your platform to ensure that 64-bit libraries are linked from the correct location, both at compile-time and at run-time. This sort of approach is more reliable than the CFLAGS / LDFLAGS stuff, since it handles more-oddball problems better, for example, when a file is preprocessed rather than compiled to a .o file and so CFLAGS is not used. _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf