V8js PHP module on Linux - can't find libv8.so
configure script can have a hard time determining the V8 version if you don't have V8 installed in the usual location (directly in /usr or /usr/local). I used: export CXXFLAGS="-I/usr/local/mydir/include -Wl,--rpath,/usr/local/mydir/lib" before running the configure script ( --with-v8js=/usr/local/mydir ) so that it could find the v8 version.
Really it's a bug in v8js that the configure script doesn't exit 1 when it can't find the V8 version.