The legacy way to build MySQL on Unix was to run
lots of parameters; make
This will still work, however ./configure created by ./BUILD/autorun.sh is just a wrapper that translates old-style autotools parameters to new style cmake parameters. Beware that the script is neither perfect nor supported. It is meant to be a temporary solution for those who need time to rewrite ./configure based scripts to native CMake.
Instead of running BUILD/autorun.sh, one can directly invoke ./cmake/configure.pl