If CMake is run after it has previously been run, it may use information that was gathered during its previous invocation. This information is stored in CMakeCache.txt. When CMake starts, it looks for that file and reads its contents if it exists, on the assumption that the information is still correct. That assumption is invalid when you reconfigure.

Each time you run CMake, you must run make again to recompile. However, you may want to remove old object files from previous builds first because they were compiled using different configuration options.

To define which C and C++ compilers to use, you can define the CC and CXX environment variables. For example:

$> CC=gcc
$> CXX=g++
$> export CC CXX

While this can be done on the command line, as just shown, you may prefer to define these values in a build script, in which case the export command is not needed.

To specify your own C and C++ compiler flags, use the CMAKE_C_FLAGS and CMAKE_CXX_FLAGS CMake options. See Compiler Flags.

To see what flags you might need to specify, invoke mysql_config with the --cflags and --cxxflags options.

To see what commands are executed during the compile stage, after using CMake to configure MySQL, run make VERBOSE=1 rather than just make.

If compilation fails, check whether the MYSQL_MAINTAINER_MODE option is enabled. This mode causes compiler warnings to become errors, so disabling it may enable compilation to proceed.

If your compile fails with errors such as any of the following, you must upgrade your version of make to GNU make:

make: Fatal error in reader: Makefile, line 18:
Badly formed macro assignment

Or:

make: file `Makefile' line 18: Must be a separator (:

Or:

pthread.h: No such file or directory

Solaris and FreeBSD are known to have troublesome make programs.

GNU make 3.75 is known to work.

The sql_yacc.cc file is generated from sql_yacc.yy. Normally, the build process does not need to create sql_yacc.cc because MySQL comes with a pregenerated copy. However, if you do need to re-create it, you might encounter this error:

"sql_yacc.yy", line xxx fatal: default action causes potential...

This is a sign that your version of yacc is deficient. You probably need to install a recent version of bison (the GNU version of yacc) and use that instead.

Versions of bison older than 1.75 may report this error:

sql_yacc.yy:#####: fatal error: maximum table size (32767) exceeded

The maximum table size is not actually exceeded; the error is caused by bugs in older versions of bison.