ref: f2a4f349a8a68d1759c180b9edb77e3dfb67c6b4 dir: /sys/src/ape/lib/ap/plan9/execl.c/
#include <unistd.h> extern char **environ; int execl(const char *name, const char *arg0, ...) { return execve(name, &arg0, environ); }