Information for installing this PECL extension may be found in the manual chapter titled Installation of PECL extensions. Additional information such as new releases, downloads, source files, maintainer information, and a CHANGELOG, can be located here: » http://pecl.php.net/package/sphinx.
  If the ./configure script generated by
  phpize is having trouble finding the libsphinxclient
  files (for example, it was installed into a custom prefix directory), use
  ./configure --with-sphinx=$PREFIX, where $PREFIX is
  installation prefix of libsphinxclient.