golang.org/x/sys v0.22.0: unix.ENOTDIR

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify golang.org/x/sys/unix.ENOTDIR in pkg:golang/golang.org/x/sys@v0.22.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.22.0
Demonstrate these symbols/APIs:
  - golang.org/x/sys/unix.ENOTDIR

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:9e551d60ccb418c1c4fd2606bb681befdfb863773829a0ca8c3775e4daeea7c6","contract":["unix.ENOTDIR is an errno constant with the expected error message","unix.Open returning unix.ENOTDIR when accessing a child path under a regular file","unix.Rmdir returning unix.ENOTDIR when called on a regular file"],"goal":"verify golang.org/x/sys/unix.ENOTDIR in pkg:golang/golang.org/x/sys@v0.22.0","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.22.0"],"schemaVersion":1,"symbols":["golang.org/x/sys/unix.ENOTDIR"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/sys@v0.22.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.22.0","symbols":["golang.org/x/sys/unix.ENOTDIR"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require golang.org/x/sys v0.22.0

golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

package main

import (
	"errors"
	"fmt"
	"os"

	"golang.org/x/sys/unix"
)

func main() {
	tmpFile, err := os.CreateTemp("", "enotdir_demo_*")
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create temp file: %v\n", err)
		os.Exit(1)
	}
	defer os.Remove(tmpFile.Name())
	defer tmpFile.Close()

	childPath := tmpFile.Name() + "/subfile"
	_, openErr := unix.Open(childPath, unix.O_RDONLY, 0)
	if !errors.Is(openErr, unix.ENOTDIR) {
		fmt.Fprintf(os.Stderr, "expected unix.ENOTDIR, got %v\n", openErr)
		os.Exit(1)
	}

	fmt.Printf("Successfully encountered unix.ENOTDIR: %v\n", openErr)
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/sys/unix.ENOTDIR in pkg:golang/golang.org/x/sys@v0.22.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.22.0"
  ],
  "symbols": [
    "golang.org/x/sys/unix.ENOTDIR"
  ]
}

package main

import (
	"errors"
	"fmt"
	"os"
	"strings"

	"golang.org/x/sys/unix"
)

func main() {
	if err := runTests(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract test failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All contract assertions passed.")
}

func runTests() error {
	// 1. unix.ENOTDIR is an errno constant with the expected error message
	if unix.ENOTDIR == 0 {
		return fmt.Errorf("expected unix.ENOTDIR to be non-zero")
	}
	errMsg := strings.ToLower(unix.ENOTDIR.Error())
	if !strings.Contains(errMsg, "not a directory") {
		return fmt.Errorf("expected error message to contain 'not a directory', got: %s", unix.ENOTDIR.Error())
	}

	// Create temporary regular file for path resolution tests
	tmpFile, err := os.CreateTemp("", "enotdir_contract_*")
	if err != nil {
		return fmt.Errorf("failed to create temporary file: %w", err)
	}
	defer os.Remove(tmpFile.Name())
	defer tmpFile.Close()

	// 2. unix.Open returning unix.ENOTDIR when accessing a child path under a regular file
	childPath := tmpFile.Name() + "/child_node"
	_, openErr := unix.Open(childPath, unix.O_RDONLY, 0)
	if openErr == nil {
		return fmt.Errorf("expected unix.Open on file subpath to fail")
	}
	if !errors.Is(openErr, unix.ENOTDIR) {
		return fmt.Errorf("expected unix.ENOTDIR, got %v", openErr)
	}

	// 3. unix.Rmdir returning unix.ENOTDIR when called on a regular file
	rmdirErr := unix.Rmdir(tmpFile.Name())
	if rmdirErr == nil {
		return fmt.Errorf("expected unix.Rmdir on regular file to fail")
	}
	if !errors.Is(rmdirErr, unix.ENOTDIR) {
		return fmt.Errorf("expected unix.ENOTDIR from rmdir, got %v", rmdirErr)
	}

	return nil
}