in reply to Building Net::SFTP on Solaris problem.
GMP was compiled 64-bit. Your Perl is 32-bit. Recompile GMP for 32-bit integers (or you can recompile perl for 64-bit). Consult GMP documentation on how to do it.
Update: The option is ABI=32, i.e., you should reconfigure GMP by
./configure ABI=32This yields
gmp-4.1.2$ file .libs/libgmp.so .libs/libgmp.so: ELF 32-bit MSB dynamic lib SPARC32PLUS Version 1, V8+ Required, UltraSPARC1 Extensions Required, dynamically linked, not stripped