hashicorp/terraform · error

failed to read state

Error message

failed to read state: %w

What it means

Thrown during PersistState after the in-memory state is serialized to a byte buffer (statefile.Write) and immediately re-read via statefile.Read to validate the round-trip and extract RootOutputValues. A failure here means the buffer that was just successfully written cannot be parsed back, which signals an internal serialization bug or memory corruption rather than a user-facing configuration problem. The %w wraps the underlying statefile.Read error.

Solutions

1. Re-run the terraform command (apply/plan) — if transient memory corruption the second attempt will succeed
2. Upgrade to the latest stable terraform release if running an alpha/nightly build that may have a state-format bug
3. File a terraform issue including both the statefile.Write success and statefile.Read error to help reproduce the format mismatch
4. If reproducible, run terraform state pull > state.json to inspect the serialized state manually and confirm it parses with your CLI version

// Before PersistState, validate the state round-trips locally:
buf := new(bytes.Buffer)
if err := statefile.Write(statefile.New(s.state, s.lineage, s.serial), buf); err != nil {
    return err
}
if _, err := statefile.Read(bytes.NewReader(buf.Bytes())); err != nil {
    // state would fail the PersistState round-trip; abort early
    return fmt.Errorf("state round-trip validation failed before persist: %w", err)
}

// Wrap PersistState in a retry for transient round-trip failures:
var lastErr error
for attempt := 0; attempt < 3; attempt++ {
    err := stateMgr.PersistState(schemas)
    if err == nil {
        break
    }
    if strings.Contains(err.Error(), "failed to read state") {
        lastErr = err
        time.Sleep(time.Duration(attempt+1) * time.Second)
        continue
    }
    return err // non-retryable
}
if lastErr != nil {
    return fmt.Errorf("persist failed after retries: %w", lastErr)
}

When it happens

Trigger: statefile.Write produces bytes that statefile.Read rejects; memory corruption affecting the bytes.Buffer between write and read; a development/alpha build with an incompatible state format version; a third-party state mutation that left the buffer in an invalid state.

Common situations: Almost never seen in production releases. Can surface in CI when testing unreleased terraform builds with state format changes, or after hardware memory errors. Users running nightly/alpha builds may encounter it during format migrations.

Related errors

• error reading output values
• failed to marshal outputs to json
• failed to translate outputs
• cannot serialize updated credentials file
• error converting output values to json

AI-assisted analysis of hashicorp/terraform@d32a084675 (2026-08-11). Data as JSON: /api/errors/f904b828887bf524. Report an issue: GitHub.

Appendix: source

Thrown at internal/cloud/state.go:219

	f := statefile.New(s.state, s.lineage, s.serial)

	var buf bytes.Buffer
	err := statefile.Write(f, &buf)
	if err != nil {
		return err
	}

	var jsonState []byte
	if schemas != nil {
		jsonState, err = jsonstate.Marshal(f, schemas)
		if err != nil {
			return err
		}
	}

	stateFile, err := statefile.Read(bytes.NewReader(buf.Bytes()))
	if err != nil {
		return fmt.Errorf("failed to read state: %w", err)
	}

	ov, err := jsonstate.MarshalOutputs(stateFile.State.RootOutputValues)
	if err != nil {
		return fmt.Errorf("failed to translate outputs: %w", err)
	}
	jsonStateOutputs, err := json.Marshal(ov)
	if err != nil {
		return fmt.Errorf("failed to marshal outputs to json: %w", err)
	}

	err = s.uploadState(s.lineage, s.serial, s.forcePush, buf.Bytes(), jsonState, jsonStateOutputs)
	if err != nil {
		s.stateUploadErr = true
		return fmt.Errorf("error uploading state: %w", err)
	}
	// After we've successfully persisted, what we just wrote is our new
	// reference state until someone calls RefreshState again.

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