I have MySQL 4.1.12 installed from binary distribution in Debian Linux and I'm trying to install freeradius 1.0.4 Include and lib path for MySQL are correct: ./configure --with-mysql-include-dir=/usr/local/mysql/include --with-mysql-l ib-dir=/usr/local/mysql/lib But output of configure script says that mysql libraries not found: creating Makefile configuring in ./drivers/rlm_sql_mysql running /bin/sh /configure --with-mysql-include-dir=/usr/local/mysql/include --with-mysql-l ib-dir=/usr/local/mysql/lib --enable-ltdl-install --cache-file=../../../../. ././config.cache --srcdir=. loading cache ../../../../.././config.cache checking for gcc... (cached) gcc checking whether the C compiler (gcc -g -O2 -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS -DOPENSSL_NO_KRB5 -Wal l -D_GNU_SOURCE -DNDEBUG ) works... yes checking whether the C compiler (gcc -g -O2 -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS -DOPENSSL_NO_KRB5 -Wal l -D_GNU_SOURCE -DNDEBUG ) is a cross-compiler... no checking whether we are using GNU C... (cached) yes checking whether gcc accepts -g... (cached) yes checking how to run the C preprocessor... (cached) gcc -E checking for mysql_config... no checking for compress in -lz... no checking for mysql/mysql.h... yes checking for mysql_init in -lmysqlclient... no configure: warning: mysql libraries not found. Use --with-mysql-lib-dir=<path>. configure: warning: sql submodule 'mysql' disabled updating cache ../../../../.././config.cache creating ./config.status creating Makefile Note that I successfully install freeradius 1.0.2 with mysql 4.1.7 the same way in another machine with Debian Linux with same configuration.