While doing a make on sphinx we got:

sphinx.cpp:16792: error: ‘m_pMysqlFields’ was not declared in this scope
sphinx.cpp:16793: error: ‘m_pMysqlResult’ was not declared in this scope
sphinx.cpp:16793: error: ‘mysql_fetch_fields’ was not declared in this scope
sphinx.cpp:16795: error: ‘m_pMysqlFields’ was not declared in this scope
make[2]: *** [sphinx.o] Error 1
make[2]: Leaving directory `/usr/local/src/sphinx-0.9.8.1/src'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/usr/local/src/sphinx-0.9.8.1/src'
make: *** [all-recursive] Error 1

simply install mysql-devel rpm and should compile fine.