Compiling MySQL 5 in Ubuntu

If when compiling MySQL5 you get an error similar to the following:

sed: can't read y.tab.c: No such file or directory
make[2]: *** [sql_yacc.cc] Error 2

Then you're probably missing the bison package.

To remedy, first install bison:

sudo apt-get install bison

Then start the mysql build again with a fresh start:

make distclean; ./configure; make

Your troubles should be over.