ERR_UNSUPPORTED_ESM_URL_SCHEME on Windows - dynamic import needs pathToFileURL

[thelandinlook]

Bug Description

The npm package fails on Windows with ERR_UNSUPPORTED_ESM_URL_SCHEME when running claude-self-reflect setup.

Environment

• OS: Windows 11
• Node: v22.19.0 (also tested v20.x - same issue)
• Package version: 2.8.10
• Installation method: npm install -g claude-self-reflect

Error

Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only URLs with a scheme in: file, data, and node are supported by the default ESM loader. On Windows, absolute paths must be valid file:// URLs. Received protocol 'c:'
at throwIfUnsupportedURLScheme (node:internal/modules/esm/load:184:11)
at defaultLoad (node:internal/modules/esm/load:82:3)
at ModuleLoader.load (node:internal/modules/esm/loader:801:12)

Root Cause

installer/setup-wizard.js line 9 uses a dynamic import with a Windows path instead of a file:// URL:

import(join(__dirname, 'setup-wizard-docker.js'));

On Windows, ESM dynamic imports require file:// URLs, not filesystem paths.

Fix

import { fileURLToPath, pathToFileURL } from 'url';
// ...
import(pathToFileURL(join(__dirname, 'setup-wizard-docker.js')).href);

Notes

• This only affects Windows users using the npm package
• Mac/Linux users are unaffected (Unix paths work with dynamic imports)
• The same pattern might exist in other files

Reproduction

1. Windows machine with Node 20+
2. npm install -g claude-self-reflect
3. claude-self-reflect setup

[ramakay]

@thelandinlook The issue has been reopened and fixed.

Root cause: The installer/setup-wizard.js used a filesystem path directly in a dynamic import on line 12, which Windows ESM loader rejects with ERR_UNSUPPORTED_ESM_URL_SCHEME. Windows requires file:// URLs for dynamic imports.

Fix applied: Updated the code to use pathToFileURL() to convert the filesystem path to a proper file:// URL before passing to import(). This ensures cross-platform compatibility.

Fixed in version: 3.0.2 (releasing shortly)

The fix converts:

import(join(__dirname, 'setup-wizard-docker.js'))

To:

const wizardPath = join(__dirname, 'setup-wizard-docker.js');
import(pathToFileURL(wizardPath).href);

Thank you for the detailed bug report with the root cause analysis. This will be available in v3.0.2.