nikcli upgrade fails on Windows: locked self-binary + swallowed Effect error (diagnosis & fix)

[SandroHub013]

nikcli upgrade fails on Windows — locked self-binary + swallowed error

A detailed diagnosis and fix for the Windows self-upgrade failure. Verified reproducible on Windows with the standalone (curl) install.

Symptom

Running nikcli upgrade (when a newer version exists) fails with a generic, unhelpful message:

┌  Upgrade
│
●  Using method: curl
│
●  From 1.228.0 → 1.229.0
│
■  Upgrade failed
│
■  An error occurred in Effect.tryPromise
│
└  Done

Root cause — two bugs, stacked

1. The self-binary is locked (the real failure)

On win32, resolveUpgradeStrategy runs the PowerShell installer:

// packages/nikcli/src/installation/index.ts
cmd = $`powershell -NoProfile -NonInteractive -Command ${strategy.script}`.env({
  ...process.env,
  NIKCLI_VERSION: target,
})

The installer (install.ps1) replaces nikcli.exe with a direct Copy-Item. But nikcli upgrade is itself the running nikcli.exe, and Windows holds an image lock on it — so the copy fails:

x  Could not write C:\Users\me\.nikcli\bin\nikcli.exe
   (Il processo non può accedere al file ... perché è in uso da un altro processo.)

The installer then exit 1.

2. The real error is swallowed by Effect.tryPromise (the bad message)

The install layer wraps upgradeImpl in a bare tryPromise:

upgrade: (method, target) => Effect.tryPromise(() => upgradeImpl(method, target)),

Effect.tryPromise(() => fn) wraps any thrown error in an UnknownException. So the typed UpgradeFailedError (which carries the useful message) is lost, and the handler in cli/cmd/upgrade.ts…

if (err instanceof Installation.UpgradeFailedError) {
  /* never matches */
} else if (err instanceof Error) prompts.log.error(err.message) // → "An error occurred in Effect.tryPromise"

…never matches and prints the generic Effect text instead of the actual reason.

The fix

A. install.ps1 (root + packages/web/public/install.ps1) — handle the locked binary

Windows lets you rename a running executable but not overwrite/delete it. So before copying, move the in-use binary aside:

function Install-File {
  param([string]$Source, [string]$Destination)
  try {
    Copy-Item -Path $Source -Destination $Destination -Force
    return $true
  } catch {
    if (-not (Test-Path $Destination)) { return $false }
    # Pick a free aside name (a stale .old may still be locked).
    $dir = Split-Path $Destination
    $base = [System.IO.Path]::GetFileName($Destination)
    $aside = Join-Path $dir "$base.old"
    if (Test-Path $aside) {
      try { Remove-Item $aside -Force -ErrorAction Stop }
      catch { $aside = Join-Path $dir ($base + "." + [System.Guid]::NewGuid().ToString("N").Substring(0,8) + ".old") }
    }
    try { Move-Item -Path $Destination -Destination $aside -Force } catch { return $false }
    try {
      Copy-Item -Path $Source -Destination $Destination -Force
      Remove-Item $aside -Force -ErrorAction SilentlyContinue # still-locked = ignored
      return $true
    } catch {
      Move-Item -Path $aside -Destination $Destination -Force -ErrorAction SilentlyContinue # rollback
      return $false
    }
  }
}

Plus, at the start of the installer, clean up binaries left aside by previous runs (now that their owning process has exited):

Get-ChildItem -Path $installDir -Filter "$App.exe*.old" -File -ErrorAction SilentlyContinue |
  ForEach-Object { Remove-Item $_.FullName -Force -ErrorAction SilentlyContinue }

Also: Fail now writes to stderr too ([Console]::Error.WriteLine), so the message is captured even when the PowerShell host discards Write-Host.

B. packages/nikcli/src/installation/index.ts — preserve the typed error

export function toUpgradeError(error: unknown): UpgradeFailedError {
  if (error instanceof UpgradeFailedError) return error
  const stderr = error instanceof Error ? error.message : String(error)
  return new UpgradeFailedError({ stderr })
}

// in the layer:
upgrade: (method, target) =>
  Effect.tryPromise({ try: () => upgradeImpl(method, target), catch: toUpgradeError }),

And capture the installer output from whichever stream actually carries it (the PowerShell installer reports via Write-Host → stdout, not stderr):

const stderr =
  strategy.type === "package-manager" && strategy.method === "choco"
    ? "not running from an elevated command shell"
    : result.stderr.toString("utf8").trim() ||
      result.stdout.toString("utf8").trim() ||
      `command exited with code ${result.exitCode}`

Verification

• Locked-binary fix (end-to-end): started nikcli serve to hold the real image lock on nikcli.exe, ran the patched installer → succeeded (rename-aside), where the old installer failed. Binary restored afterwards.
• Error-message fix (end-to-end): forced a failure with a non-existent version. Before: An error occurred in Effect.tryPromise. After: the real installer output — x Failed to download nikcli-ai-windows-x64.zip.
• Rename sanity check: confirmed a running nikcli.exe can be Move-Item'd on Windows (the basis of the fix), unlike a plain FileStream lock.
• Unit tests: added 3 cases for toUpgradeError (preserves UpgradeFailedError by identity, wraps plain Error, stringifies non-Error). bun test test/installation/effect-service.test.ts → 27 pass / 0 fail.
• Typecheck: no new errors (the two pre-existing solid-js/store errors in packages/plugin are unrelated).

Notes

• When upgrading while a nikcli session is running, that session keeps executing from the renamed nikcli.exe.old until it exits; the .old is removed on the next install/launch. This is expected and safe.
• For the fix to reach existing installs, the patched install.ps1 must be redeployed to nikcli.store/install.ps1, and a new release must be cut so the compiled binary contains the installation/index.ts change.

Files changed

• install.ps1 · packages/web/public/install.ps1 — Install-File rename-aside, stale-.old cleanup, Fail → stderr, cache-bust.
• packages/nikcli/src/installation/index.ts — toUpgradeError, tryPromise({try,catch}), stdout/stderr capture.
• packages/nikcli/test/installation/effect-service.test.ts — coverage for toUpgradeError.

Happy to open a PR with these changes if that's useful.

[nikomatt69]

/nikcli di che e fixata e mostra da che pr