Hello Mirek,

thanks for the reply.
I already tried to remove the PLATFORM_POSIX but no success.

This is the full error message:

/Users/mac/upp.src/uppsrc/mysql/mysql.h (18): warning: non-portable path to file '<MySql/MySql.h>'; specified path differs in case from file name on disk [-Wnonportable-include-path]
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (1): In file included from /Users/mac/upp.src/uppsrc/MySql/MySql.cpp:1:
(): #include <mysql/mysql.h>
(): <MySql/MySql.h>
/Users/mac/upp.src/uppsrc/mysql/mysql.h (46): error: unknown type name 'MYSQL'
/Users/mac/upp.src/uppsrc/mysql/mysql.h (75): error: unknown type name 'MYSQL'
/Users/mac/upp.src/uppsrc/mysql/mysql.h (68): error: use of undeclared identifier 'MYSQL_PORT'
/Users/mac/upp.src/uppsrc/mysql/mysql.h (84): error: cannot initialize object parameter of type 'Upp::SqlSession' with an expression of type 'Upp::MySqlSession'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (24): error: unknown type name 'MYSQL'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (26): error: unknown type name 'MYSQL_RES'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (27): error: unknown type name 'MYSQL_ROW'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (39): error: unknown type name 'MYSQL'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (50): error: use of undeclared identifier 'mysql_library_init'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (54): error: use of undeclared identifier 'mysql_library_end'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (59): error: expected expression
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (59): error: use of undeclared identifier 'MYSQL'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (64): error: no matching constructor for initialization of 'Upp::Sql'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (103): error: use of undeclared identifier 'MYSQL_PORT'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (142): error: cannot initialize object parameter of type 'Upp::SqlSession' with an expression of type 'Upp::MySqlSession'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (172): error: out-of-line definition of 'Begin' does not match any declaration in 'Upp::MySqlSession'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (216): error: no matching constructor for initialization of 'Upp::Sql'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (225): error: no matching constructor for initialization of 'Upp::Sql'
/Users/mac/upp.src/uppsrc/MySql/MySql.cpp (234): error: no matching constructor for initialization of 'Upp::Sql'

You get the same if you try to compile the mysql package test case coming with U++.

Googling on internet I did several things (there is no unanimous agreement)

1) upgrade brew

brew update --verbose

it may takes some minute to upgrade everything (at least on my Mac mini)

2) installed several libraries, one by one because each of them didn't work

brew install mysql-connector-cc
brew install mysql-connector-c
brew install mysql-client

At the end I had a MYSQL folder in
/usr/local/Cellar/mysql
/usr/local/Cellar/mysql-client
/usr/local/Cellar/mysql-connector-c++
/usr/local/opt/mysql

each one with their include and lib folder.
I tried to point theide in all includes but with no luck.
I hope this info can be useful.

thanks,
Luigi