{"id":"530c86dec2e75926","repo":"rust-lang/cargo","slug":"couldn-t-find-username","errorCode":null,"errorMessage":"couldn't find username","messagePattern":"couldn't find username","errorType":"validation","errorClass":"anyhow::Error","httpStatus":null,"severity":"info","filePath":"src/sources/git/utils.rs","lineNumber":1653,"sourceCode":"                    debug!(\"github fast path is already a full commit hash {rev}\");\n                    return Ok(FastPathRev::NeedsFetch(oid));\n                }\n                rev\n            } else {\n                debug!(\"can't use github fast path with `rev = \\\"{}\\\"`\", rev);\n                return Ok(FastPathRev::Indeterminate);\n            }\n        }\n    };\n\n    // This expects GitHub urls in the form `github.com/user/repo` and nothing\n    // else\n    let mut pieces = url\n        .path_segments()\n        .ok_or_else(|| anyhow!(\"no path segments on url\"))?;\n    let username = pieces\n        .next()\n        .ok_or_else(|| anyhow!(\"couldn't find username\"))?;\n    let repository = pieces\n        .next()\n        .ok_or_else(|| anyhow!(\"couldn't find repository name\"))?;\n    if pieces.next().is_some() {\n        anyhow::bail!(\"too many segments on URL\");\n    }\n\n    // Trim off the `.git` from the repository, if present, since that's\n    // optional for GitHub and won't work when we try to use the API as well.\n    let repository = repository.strip_suffix(\".git\").unwrap_or(repository);\n\n    let url = format!(\n        \"https://api.github.com/repos/{}/{}/commits/{}\",\n        username, repository, github_branch_name,\n    );\n    debug!(\"attempting GitHub fast path for {}\", url);\n    let mut request =\n        Request::get(url).header(http::header::ACCEPT, \"application/vnd.github.3.sha\");","sourceCodeStart":1635,"sourceCodeEnd":1671,"githubUrl":"https://github.com/rust-lang/cargo/blob/0e07a155371a6ce88ae53a2c00df940280c09a67/src/sources/git/utils.rs#L1635-L1671","documentation":"In `github_fast_path`, after `url.path_segments()` succeeds, `pieces.next()` returned `None` for the username segment — i.e. the GitHub URL had a path like `github.com/` (empty). Like 162, this is an internal fast-path error: the doc comment says the function should never cause an actual failure and the caller logs the `Err` at `debug!` and falls back to a regular fetch. It is not normally surfaced.","triggerScenarios":"A git source URL whose host is `github.com` but whose path is empty or only slashes (e.g. `https://github.com/`). Triggers only during the GitHub fast-path probe in `fetch()`.","commonSituations":"Typo'd git URL in `Cargo.toml` (`git = \"https://github.com\"` with no user/repo); a bad `insteadOf` rewrite stripping the path. Because the error is swallowed you typically only notice it as a subsequent real failure when the fallback fetch runs.","solutions":["Fix the dependency URL to include user and repo: `https://github.com/<user>/<repo>`.","No urgent action otherwise — Cargo falls back to a normal fetch automatically; investigate only if the fallback itself fails."],"exampleFix":"# before\n[dependencies]\nfoo = { git = \"https://github.com\" }\n\n# after\nfoo = { git = \"https://github.com/org/foo\" }","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"// Same swallowed-fast-path pattern as 162.\nmatch github_fast_path(repo, url, reference, gctx) {\n    Ok(r) => r,\n    Err(e) => { debug!(\"failed to check github {:?}\", e); /* normal fetch */ }\n}","preventionTips":["Validate git URLs include a user segment before passing to Cargo internals.","Treat any error from the fast path as non-fatal."],"tags":["cargo","git","github-fast-path","url","internal"],"analyzedSha":"0e07a155371a6ce88ae53a2c00df940280c09a67","analyzedAt":"2026-08-06T01:46:58.334Z","schemaVersion":2}