This file contains any messages produced by compilers while running configure, to aid debugging if configure makes a mistake. configure:607:1: warning: return type defaults to 'int' [-Wimplicit-int] configure: In function 'main': configure:694:67: warning: implicit declaration of function 'exit' [-Wimplicit-function-declaration] configure:694:67: warning: incompatible implicit declaration of built-in function 'exit' configure:694:67: note: include '' or provide a declaration of 'exit' configure:695:1: warning: incompatible implicit declaration of built-in function 'exit' configure:695:1: note: include '' or provide a declaration of 'exit'