Skill-pack git clone sends Authorization: Bearer to github.com git transport (needs Basic) → private-repo clones fail with a valid PAT

[DrDriftwood]

Summary

Registering a private github.com repo as a skill pack fails to authenticate. QM's git clone sends the credential as Authorization: Bearer <token>, but GitHub's git-over-HTTPS transport does not honor the Bearer scheme — it only accepts HTTP Basic. The request therefore authenticates as anonymous and the clone aborts, even with a valid fine-grained PAT.

Version

Observed at pinned commit 7f2c916360f1797a8ff2a77ce2ce40c5fabab087.

Evidence (dummy credentials only — no real secrets)

Endpoint https://github.com/<owner>/<private-repo>/info/refs?service=git-upload-pack:

• No auth → HTTP 401, WWW-Authenticate: Basic realm="GitHub".
• Authorization: Bearer <dummy> → HTTP 401, WWW-Authenticate: Basic realm="GitHub" — byte-identical headers to the anonymous case, so Bearer is not processed on the git transport.
• Authorization: Basic base64("x-access-token:<PAT>") → GitHub processes the Basic scheme (a valid PAT returns 200).

Root cause (source)

src/skills/pack-fetcher.ts, resolvePackAuth (~L132-134):

const header = credential.injection?.header?.trim() || "Authorization";
const scheme = credential.injection?.scheme ?? "Bearer ";
return { header, value: `${scheme}${credential.secret}`, ... };

Applied via http.extraHeader in gitEnv. For a github.com git clone, Bearer yields a header GitHub ignores. The blank-slug fallback (connectorHostFor("github.com") → api.github.com, ~L58-61 / L136-139) also returns Bearer ${token} → identical failure on the clone. With GIT_TERMINAL_PROMPT=0, git falls through to credential-fill, cannot prompt, and aborts:

fatal: could not read Username for 'https://github.com': terminal prompts disabled

(exit 128).

Scope note

The Bearer default is correct for the REST API (api.github.com) — see src/api/credential-broker.ts (~L62-63). Only the git-clone path for github.com needs Basic.

Suggested fix

For github.com git-over-HTTPS remotes, authenticate with HTTP Basic — username x-access-token, PAT as password (Authorization: Basic base64("x-access-token:" + PAT)), or inject equivalent URL userinfo. Keep the Bearer default for api.github.com REST calls.

Workaround (no code change, admin API only)

Set the credential's injection.scheme = "Basic " and store the secret pre-encoded as base64("x-access-token:" + PAT), so QM emits a valid Authorization: Basic <base64>. The admin CREATE UI does not expose injection.scheme, so this is API-only.

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Filed from a downstream deployment. Internal tracker ref: LAR-989.