Validate GitHub username exists during setup validation

[Copilot]

Users with typos in their GitHub username (e.g., "medynwd" instead of "Medwynd") weren't getting clear feedback during validation. The script only checked if the full repo path existed, making it ambiguous whether the username or repo name was wrong.

Changes

• Added _validate_github_user(): Validates GitHub user exists via /users/{owner} API endpoint before checking repository
• Updated validation flow: Check user existence first, then repository existence
• Improved error messages: Distinguish between "user not found" vs "repo not found in user's account"

Example

Before - ambiguous error:

❌ GitHub repo not found (404)
   Check that the repo is public and the owner/repo is spelled correctly

After - pinpoints the issue:

❌ GitHub user 'medynwd' not found (404)
   Check that the username is spelled correctly

Trade-offs

Adds one extra GitHub API call per validation run. Rate limit errors (403) are handled gracefully to avoid false negatives.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/users/EmilStenstrom
  • Triggering command: /usr/bin/python3 python3 (http block)
• https://api.github.com/users/github
  • Triggering command: /usr/bin/python3 python3 (http block)
• https://api.github.com/users/medynwd
  • Triggering command: /usr/bin/python3 python3 (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Validate the the GitHub user is valid as part of the validation script</issue_title>
<issue_description>> @Medwynd In the logs it seems to look at the "medynwd" username. Does it use the wrong github username?

In your config, you should put Medwynd/mybgg as github_repo.

Good catch! Yeah that was it, I fat fingered it. Maybe a check could be added to the validate script since that passed and said everything was good to go?

Originally posted by @Medwynd in #96</issue_description>

<agent_instructions>I think we already solved this?</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Validate the the GitHub user is valid as part of the validation script #97

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[EmilStenstrom]

@copilot I've added https://api.github.com to the allowlist. Verify that this works.

[Copilot]

@copilot I've added https://api.github.com to the allowlist. Verify that this works.

Verified! The GitHub API is now accessible and the validation is working correctly.

Test Results:

✅ Valid usernames (e.g., 'EmilStenstrom', 'Medwynd') are successfully validated
✅ Invalid usernames (e.g., 'medynwd' - the typo from the original issue) are properly caught with clear error messages

The validation now correctly:

1. Checks if the GitHub user exists before checking the repository
2. Returns a clear "user not found" message when the username is misspelled
3. Distinguishes between username errors and repository errors

Test Case: Invalid username (typo from issue)
🔍 Checking GitHub user 'medynwd' exists...
❌ GitHub user 'medynwd' not found (404)
   Check that the username is spelled correctly

The implementation solves the original issue where users with typos in their GitHub username weren't getting clear feedback during validation.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• cors-proxy.mybgg.workers.dev
  • Triggering command: /usr/bin/python3 python3 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)