If you are sure that Module:Build is installed already in the system, then you have to add the path in PERL5LIB so that Sys-Filesystem willl find it. If Sys-Filesystem does not find where your Module:Build installed then it will end up with an error always. Example
PERL5LIB="${GATEWAY_FRAMEWORK}/perl_extensions/lib/site_perl:${GATEWAY
+_FRAMEWORK}/parsersrc"