{"id":"d92b5079268b6e0d","repo":"rust-lang/cargo","slug":"no-path-segments-on-url","errorCode":null,"errorMessage":"no path segments on url","messagePattern":"no path segments on url","errorType":"validation","errorClass":"anyhow::Error","httpStatus":null,"severity":"info","filePath":"src/sources/git/utils.rs","lineNumber":1650,"sourceCode":"                // either. (This ensures that we always attempt to fetch the\n                // commit directly even if we can't reach the GitHub API.)\n                if let Some(oid) = rev_to_oid(rev) {\n                    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    );","sourceCodeStart":1632,"sourceCodeEnd":1668,"githubUrl":"https://github.com/rust-lang/cargo/blob/0e07a155371a6ce88ae53a2c00df940280c09a67/src/sources/git/utils.rs#L1632-L1668","documentation":"Inside `github_fast_path` (src/sources/git/utils.rs:1586) Cargo parses the GitHub repository URL and calls `Url::path_segments()`, which returns `None` for URLs that cannot have a base / have no hierarchical path (e.g. `data:` / opaque / non-standard schemes that the `url` crate treats as cannot-be-a-base). This error is essentially defensive: the function's own doc comment states it 'should never cause an actual failure', and the sole caller (`fetch()` at src/sources/git/utils.rs:1035) catches `Err`, logs it at `debug!`, and falls back to the normal fetch path. In practice it is swallowed, not surfaced to the user.","triggerScenarios":"A git dependency URL that `is_github()` matches as a GitHub host yet has no parseable path segments — e.g. a malformed `github.com` URL, or an edge case produced by URL rewriting/mirroring config. Observed only when running cargo with `CARGO_LOG=cargo::sources::git=debug` or higher.","commonSituations":"Custom `insteadOf` git URL rewrites, mirror/proxy configurations that transform `https://github.com/...` into something opaque, or hand-edited registry entries. Almost never seen because the result is discarded.","solutions":["No user action required — this is a swallowed fast-path miss; Cargo proceeds to a normal fetch.","If you see it flooding debug logs, correct the git dependency URL in `Cargo.toml` / `[source]` mapping to a well-formed `https://github.com/user/repo` form.","Check `.cargo/config.toml` `[url]` / `insteadOf` rewrites for a rule that mangles the GitHub URL."],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"// Cargo itself already swallows this — pattern for callers of github_fast_path:\nmatch github_fast_path(repo, url, reference, gctx) {\n    Ok(rev) => { /* use fast-path result */ }\n    Err(e) => {\n        tracing::debug!(\"failed to check github {:?}\", e);\n        // fall through to a normal fetch; never propagate fast-path errors\n    }\n}","preventionTips":["Never propagate errors out of `github_fast_path` — its contract says callers must ignore Err.","Keep git dependency URLs in canonical `https://github.com/<user>/<repo>` form.","Audit `[url]`/`insteadOf` rewrites so they don't mangle GitHub URLs into opaque ones."],"tags":["cargo","git","github-fast-path","url","internal"],"analyzedSha":"0e07a155371a6ce88ae53a2c00df940280c09a67","analyzedAt":"2026-08-06T01:46:58.334Z","schemaVersion":2}