Git's proxyAuthMethod Needs a Proxy Username

You add http.proxyAuthMethod, retry the clone, and still see 407. The setting has a documented condition that is easy to miss: the configured proxy string must contain a username.

The username does not have to be accompanied by a password literal in the URL. Git can acquire a missing password through its credential machinery. The routing identity and the authentication method still need to refer to the intended proxy.

Inspect four inputs together

1. The effective proxy URI, with its password removed.
2. The method selected for that proxy.
3. Any per-remote override or GIT_HTTP_PROXY_AUTHMETHOD environment override.
4. The Git version and capabilities of its HTTP backend.

Current Git documents methods including anyauth, Basic, Digest, Negotiate and NTLM. Choosing one does not add missing support to the linked backend. Nor should a corporate administrator have to weaken the proxy's policy because a client was configured for another method.

Older reports include versions that did not implement the option being copied. An arbitrary configuration key can be stored without providing evidence that the running transfer uses it. Read the versioned documentation and the redacted exchange.

Finally, repository credentials are a later relationship. A Git hosting token does not satisfy a proxy's challenge. Disabling repository TLS verification likewise does not make the proxy accept the chosen authentication scheme. Establish that exchange first, then diagnose any repository response that follows.