hashicorp/nomad · critical

failed to detect executable: %v

Error message

failed to detect executable: %v

What it means

Self() resolves the current process executable path via os.Executable() inside a sync.Once and caches it. If os.Executable() fails, the process panics immediately because Nomad cannot locate its own binary to relaunch helper subprocesses (drivers, exec tasks). This is a programming/environment-level failure, not a recoverable runtime error.

Source

Thrown at helper/subproc/self.go:25

	"fmt"
	"os"
	"os/exec"
	"strings"
	"sync"
)

var (
	// executable is the executable of this process
	executable string
	once       sync.Once
)

// Self returns the path to the executable of this process.
func Self() string {
	once.Do(func() {
		s, err := os.Executable()
		if err != nil {
			panic(fmt.Sprintf("failed to detect executable: %v", err))
		}

		// when running tests, we need to use the real nomad binary,
		// and make sure you recompile between changes!
		if strings.HasSuffix(s, ".test") {
			if s, err = exec.LookPath("nomad"); err != nil {
				panic(fmt.Sprintf("failed to find nomad binary: %v", err))
			}
		}
		executable = s
	})
	return executable
}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Restore the deleted or moved binary at its original path, or restart the process from a valid binary location
2. Check that /proc is mounted and readable (Linux) so /proc/self/exe resolution works
3. Run Nomad in a standard filesystem environment; avoid exotic chroot setups that hide the executable
4. Update Nomad; if reproducible in a normal environment, file a bug with the wrapped os.Executable() error

if _, err := os.Executable(); err != nil { /* restart from a known-good binary or abort before calling subproc users */ }

defer func() { if r := recover(); r != nil { if s, ok := r.(string); ok && strings.Contains(s, "failed to detect executable") { log.Fatalf("environment error: %v", s) }; panic(r) } }()

When it happens

Trigger: Calling helper/subproc.Self() (directly or via any code that spawns subprocesses) when os.Executable() returns an error, e.g. the executable file was deleted after the process started, or the OS lookup fails.

Common situations: Running a Nomad binary that was replaced/deleted on disk while running (package upgrades), running in restricted container environments where /proc cannot be read, or unusual exec environments where /proc/self/exe is unavailable.

Related errors

• unable to read rooted allocation directory
• plugin not found
• plugin not executable
• ErrPluginNotExists
• alloc dir must be absolute

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/8dafbce3e0d0fde5. Report an issue: GitHub.