hashicorp/terraform · error

Error saving temporary state: %s

Error message

Error saving temporary state: %s

What it means

Returned by backendMigrateNonEmptyConfirm's saveHelper when writing the SOURCE state to a temp file fails (saveHelper at line 512-515, called for source at line 520). The statemgr.NewFilesystem(path).WriteState(source) call errored, so the comparison files for the confirmation prompt couldn't be produced.

Source

Thrown at internal/command/meta_backend_migrate.go:521

	// Save both to a temporary
	td, err := os.MkdirTemp("", "terraform")
	if err != nil {
		return false, fmt.Errorf("Error creating temporary directory: %s", err)
	}
	defer os.RemoveAll(td)

	// Helper to write the state
	saveHelper := func(n, path string, s *states.State) error {
		mgr := statemgr.NewFilesystem(path)
		return mgr.WriteState(s)
	}

	// Write the states
	sourcePath := filepath.Join(td, fmt.Sprintf("1-%s.tfstate", opts.SourceType))
	destinationPath := filepath.Join(td, fmt.Sprintf("2-%s.tfstate", opts.DestinationType))
	if err := saveHelper(opts.SourceType, sourcePath, source); err != nil {
		return false, fmt.Errorf("Error saving temporary state: %s", err)
	}
	if err := saveHelper(opts.DestinationType, destinationPath, destination); err != nil {
		return false, fmt.Errorf("Error saving temporary state: %s", err)
	}

	// Ask for confirmation
	var inputOpts *terraform.InputOpts
	if opts.DestinationType == "cloud" {
		appName := "HCP Terraform"
		if cloudBackend, ok := opts.Destination.(*cloud.Cloud); ok {
			appName = cloudBackend.AppName()
		}
		inputOpts = &terraform.InputOpts{
			Id:    "backend-migrate-to-tfc",
			Query: "Do you want to copy existing state to HCP Terraform?",
			Description: fmt.Sprintf(
				strings.TrimSpace(inputBackendMigrateNonEmptyCloud),
				opts.SourceType, sourcePath, destinationPath, appName),

View on GitHub (pinned to c9def3e214)

Solutions

1. Free disk space on the temp volume and retry.
2. Set TMPDIR to a local writable disk (avoid network filesystems for temp).
3. Disable or exempt terraform from AV scanners that lock new files.
4. Verify write permissions on the temp dir for the running user.
5. Retry; if persistent, capture the inner error for the exact write failure code.

Example fix

# before: write source state to /tmp fails (NFS hiccup)
#   Error saving temporary state: ... write: I/O error
# after: use a local disk for TMPDIR
export TMPDIR=/local/tmp
terraform init

# Verify temp dir is writable AND has space for at least the largest state.
maxstate=$(terraform state pull 2>/dev/null | wc -c)
avail=$(df -P "${TMPDIR:-/tmp}" | awk 'NR==2{print $4}')
[ "$((avail*1024))" -gt "$((maxstate*3))" ] || { echo 'not enough temp space for both states'; exit 1; }
terraform init

# On temp write failure, switch TMPDIR and retry.
terraform init 2>/tmp/init.err || {
  grep -q 'Error saving temporary state' /tmp/init.err || exit 1
  export TMPDIR="$HOME/.tf-tmp"; mkdir -p "$TMPDIR"
  terraform init
}

When it happens

Trigger: After the temp dir was created successfully, writing the source .tfstate file fails: disk fills between mkdir and write, write permission on the temp subdir revoked, path too long, or WriteState encounters an internal serialization error. Wrapped at line 521.

Common situations: Disk nearly full — mkdir succeeds but write fails; antivirus/scanner locking newly created files on Windows; NFS/ network filesystem write hiccup; SELinux relabeling denying the write.

Related errors

• Error creating temporary directory: %s
• Error copying state from the previous %q backend to the newl
• Can't ask approval for state migration when interactive inpu
• Migrating state from HCP Terraform or Terraform Enterprise t
• error deleting workspace %s: %w

AI-assisted analysis of hashicorp/terraform@c9def3e214 (2026-08-07). Data as JSON: /api/errors/5937a9b6b0dc76e9. Report an issue: GitHub.