Commit
631923e used a few macros from sys/wait.h without including
it. On Linux, they were also defined in stdlib.h, but on FreeBSD
the build failed:
../../tests/commandtest.c: In function 'test1':
warning: implicit declaration of function 'WIFEXITED'
warning: nested extern declaration of 'WIFEXITED' [-Wnested-externs]
#include <unistd.h>
#include <signal.h>
#include <sys/stat.h>
+#include <sys/wait.h>
#include <fcntl.h>
#include "testutils.h"