t.Skip("skipping test: gcc is missing")
	}

	tmpdir := t.TempDir()

	dir0, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	defer os.Chdir(dir0)

	const src = `
#include <stdint.h>
#include <windows.h>

uintptr_t cfunc(void) {
   SetLastError(123);
   return 0;
}
`
	srcname := "nojack.c"

int ioctl(int, int, uintptr_t);
int fcntl(uintptr_t, int, uintptr_t);
int fsync_range(int, int, long long, long long);
int acct(uintptr_t);
int chdir(uintptr_t);
int chroot(uintptr_t);
int close(int);
int dup(int);
void exit(int);
int faccessat(int, uintptr_t, unsigned int, int);
int fchdir(int);
int fchmod(int, unsigned int);
int fchmodat(int, uintptr_t, unsigned int, int);
int fchownat(int, uintptr_t, int, int, int);

//go:cgo_import_dynamic libc_Adjtime adjtime "libc.so"
//go:cgo_import_dynamic libc_Chdir chdir "libc.so"
//go:cgo_import_dynamic libc_Chmod chmod "libc.so"
//go:cgo_import_dynamic libc_Chown chown "libc.so"
//go:cgo_import_dynamic libc_Chroot chroot "libc.so"
//go:cgo_import_dynamic libc_Close close "libc.so"
//go:cgo_import_dynamic libc_Dup dup "libc.so"
//go:cgo_import_dynamic libc_Fchdir fchdir "libc.so"
//go:cgo_import_dynamic libc_Fchmod fchmod "libc.so"

				goto childerror
			}

			r1, _, _ = RawSyscall(SYS_CLOSE, uintptr(envfd), 0, 0)

			if int32(r1) == -1 {
				goto childerror
			}
		}
	}

	// Chdir
	if dir != nil {
		r1, _, _ = RawSyscall(SYS_CHDIR, uintptr(unsafe.Pointer(dir)), 0, 0)
		if int32(r1) == -1 {
			goto childerror
		}
	}

	// Pass 1: look for fd[i] < i and move those up above len(fd)

}

/*
 * Direct access
 */

//sys	Acct(path string) (err error)
//sys	Chdir(path string) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(oldfd int) (fd int, err error)
//sys	Exit(code int)
//sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
//sys	Fchdir(fd int) (err error)
//sys	Fchmod(fd int, mode uint32) (err error)

//sys	CapEnter() (err error)
//sys	capRightsGet(version int, fd int, rightsp *CapRights) (err error) = SYS___CAP_RIGHTS_GET
//sys	capRightsLimit(fd int, rightsp *CapRights) (err error)
//sys	Chdir(path string) (err error)
//sys	Chflags(path string, flags int) (err error)
//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)

//sys	Adjtime(delta *Timeval, olddelta *Timeval) (err error)
//sys	Chdir(path string) (err error)
//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Fchdir(fd int) (err error)
//sys	Fchmod(fd int, mode uint32) (err error)

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func Fchdir(fd int) (err error) {
	_, _, e1 := syscall(abi.FuncPCABI0(libc_fchdir_trampoline), uintptr(fd), 0, 0)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

func libc_fchdir_trampoline()

//go:cgo_import_dynamic libc_fchdir fchdir "libc.so"

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

 */

//sys	Acct(path string) (err error)
//sys	Chdir(path string) (err error)
//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
//sys	Fchdir(fd int) (err error)

		}

		for _, c = range sys.AmbientCaps {
			_, _, err1 = RawSyscall6(SYS_PRCTL, PR_CAP_AMBIENT, uintptr(PR_CAP_AMBIENT_RAISE), c, 0, 0, 0)
			if err1 != 0 {
				goto childerror
			}
		}
	}

	// Chdir
	if dir != nil {
		_, _, err1 = RawSyscall(SYS_CHDIR, uintptr(unsafe.Pointer(dir)), 0, 0)
		if err1 != 0 {
			goto childerror
		}
	}

	// Parent death signal
	if sys.Pdeathsig != 0 {