+ dnl We expect to see the declaration of sleep() in a header file.
+ dnl Older versions of mingw have a sleep() function that is an alias to
+ dnl _sleep() in MSVCRT. It has a different signature than POSIX sleep():
+ dnl it takes the number of milliseconds as argument and returns void.
+ dnl mingw does not declare this function.
+ AC_CHECK_DECLS([sleep], , , [#include <unistd.h>])
+ if test $ac_cv_have_decl_sleep != yes; then