Files
hermes-agent/skills/github/github-auth
Teknium 197a18314f fix: warn agents off driving interactive console TUIs via pty on Windows (#84364)
* fix: warn agents off driving interactive console TUIs via pty on Windows

Driving 'gh auth login' (and other survey-style console TUIs) through a
pty background process on Windows silently hangs: these programs read
Win32 console key events via ReadConsoleInput, not the stdin byte
stream, so Enter keypresses submitted over process stdin never register.
The agent-visible symptom is a prompt frozen at 'Press Enter to open
browser...' while the user sees nothing, and a turn interrupt then kills
the process, invalidating any device code the user already entered on
github.com.

Two guidance fixes, both proven in a live session on Windows 10:

- agent/prompt_builder.py: extend _WINDOWS_BASH_SHELL_HINT to steer
  agents toward non-interactive paths (flags, --with-token, config
  files, curl-polled OAuth device flow) instead of answering console
  prompts programmatically.
- skills/github/github-auth: document the pitfall and add the manual
  OAuth device-flow procedure (curl against gh's public client_id,
  poll for the token, finish with 'gh auth login --with-token'), which
  succeeded first try after two interactive attempts hung.

* fix: send CRLF for Enter on Windows PTY submit; correct root cause in guidance

Review feedback (helix4u) was right on both counts:

1. Root cause correction. gh's 'Press Enter to open browser' prompt is
   waitForEnter -> bufio.Scanner reading stdin, not a survey/console-API
   prompt. The real bug is ours: submit_stdin appended a bare \n, and
   through pywinpty/ConPTY a lone \n is not delivered as a line
   terminator, so the child's blocking line read never returns. Verified
   empirically against pywinpty 2.0.15 with a readline() child:
   \n -> hang, \r -> line delivered, \r\n -> line delivered.

   Fix: submit_stdin now appends \r\n for Windows PTY sessions (POSIX
   PTYs and Popen pipes keep \n). Windows-only regression tests cover
   the PTY and pipe branches.

2. Prompt hint rewritten: instead of claiming Windows console TUIs
   cannot be driven, it now says to use process(submit) rather than raw
   writes with bare \n, and to prefer non-interactive paths when a CLI
   offers one.

3. Skill device flow rewritten as an executable script: parses the
   device-code response, polls per the returned interval, handles
   authorization_pending / slow_down (+5s per GitHub docs) /
   expired_token / access_denied / unexpected responses, pipes the token
   straight into gh without echoing it, and drops the undocumented
   workflow scope (repo,read:org,gist is the documented minimum for
   gh auth login --with-token). The pitfall note is narrowed to the
   reproduced condition.
2026-08-12 01:15:17 -07:00
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