login_setenv
if (login_setenv("XDG_RUNTIME_DIR", rundir, pwd, 0) != 0) {
static int login_setenv(char *, char *, const struct passwd *, int);
error = login_setenv("PATH", path ? path : _PATH_DEFPATH, pwd, 1);
if ((error = login_setenv(beg, value, pwd, 0)) != 0) {