{"record":{"id":"4bfa2079fede7f3c","repo":"tauri-apps/tauri","slug":"parsed-syn-path-has-no-segment","errorCode":null,"errorMessage":"parsed syn::Path has no segment","messagePattern":"parsed syn::Path has no segment","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/tauri-macros/src/command/mod.rs","lineNumber":23,"sourceCode":"use proc_macro2::Ident;\nuse syn::{Path, PathSegment};\n\npub use self::{handler::Handler, wrapper::wrapper};\n\nmod handler;\nmod wrapper;\n\n/// The autogenerated wrapper ident.\nfn format_command_wrapper(function: &Ident) -> Ident {\n  quote::format_ident!(\"__cmd__{}\", function)\n}\n\n/// This function will panic if the passed [`syn::Path`] does not have any segments.\nfn path_to_command(path: &mut Path) -> &mut PathSegment {\n  path\n    .segments\n    .last_mut()\n    .expect(\"parsed syn::Path has no segment\")\n}\n","sourceCodeStart":5,"sourceCodeEnd":25,"githubUrl":"https://github.com/tauri-apps/tauri/blob/460ec35447493200d64290dd7f015d5a91d0fd58/crates/tauri-macros/src/command/mod.rs#L5-L25","documentation":"path_to_command in tauri-macros unwraps the last segment of a parsed syn::Path and panics if the path is empty. The doc comment states this panic is intentional: the helper's contract requires a non-empty path, and callers always pass paths derived from valid command references.","triggerScenarios":"Invoking the command macro machinery (wrapper/handler generation) with a syn::Path containing no segments — an internal contract violation from malformed macro input.","commonSituations":"Only via proc-macro bugs or generated code producing empty paths; end users see it as a tauri-macros compile panic, usually fixed by upgrading.","solutions":["Update tauri-macros to the latest version","Verify command reference paths in attributes are fully qualified and non-empty","Reduce to a minimal repro and report upstream if the panic persists"],"exampleFix":"// before\n// empty path passed through generated code\nlet path = syn::parse_str::<syn::Path>(\"#\").unwrap();\npath_to_command(&mut path);\n// after\nlet path = syn::parse_str::<syn::Path>(\"my_crate::command_name\").unwrap();\npath_to_command(&mut path);","handlingStrategy":"fallback","validationCode":null,"typeGuard":"fn path_has_segments(p: &syn::Path) -> bool { !p.segments.is_empty() }","tryCatchPattern":"// compile-time panic from proc macro; mitigate via version pinning\n// Cargo.toml\ntauri = \"= <known-good-version>\"  // upgrade to latest before investigating further","preventionTips":["Ensure all paths passed to command-macro helpers are fully qualified and non-empty","Keep macro crates updated together with tauri core"],"tags":["proc-macro","compile-time","tauri","invariant"],"backgroundTag":"internal-invariant-violation","analyzedSha":"460ec35447493200d64290dd7f015d5a91d0fd58","analyzedAt":"2026-09-18T23:55:51.277Z","contentChangedAt":"2026-09-18T23:55:51.277Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}