zed-industries/zed · error

missing cpp/semantic_token_rules.json

Error message

missing cpp/semantic_token_rules.json

What it means

Panics because the embedded-file lookup grammars::get_file("cpp/semantic_token_rules.json") returned None: the JSONC rules file was not found in the compiled-in grammars assets. Since the file is vendored into the binary, this indicates the asset was not included at build time (packaging/extension build issue), not a runtime environment problem.

Source

Thrown at crates/languages/src/cpp.rs:5

use settings::SemanticTokenRules;

pub(crate) fn semantic_token_rules() -> SemanticTokenRules {
    let content = grammars::get_file("cpp/semantic_token_rules.json")
        .expect("missing cpp/semantic_token_rules.json");
    let json = std::str::from_utf8(&content.data).expect("invalid utf-8 in semantic_token_rules");
    settings::parse_json_with_comments::<SemanticTokenRules>(json)
        .expect("failed to parse cpp semantic_token_rules.json")
}

#[cfg(test)]
mod tests {
    use gpui::{AppContext as _, BorrowAppContext, TestAppContext};
    use language::{AutoindentMode, Buffer};
    use settings::SettingsStore;
    use std::num::NonZeroU32;
    use unindent::Unindent;

    #[gpui::test]
    async fn test_cpp_autoindent_switch_case(cx: &mut TestAppContext) {
        cx.update(|cx| {
            let test_settings = SettingsStore::test(cx);
            cx.set_global(test_settings);

View on GitHub (pinned to f4178619ac)

Solutions

1. Verify cpp/semantic_token_rules.json is present in the grammars assets and included by the build
2. Rebuild the extensions/grammars crate so assets are re-embedded
3. Replace expect with a warning log returning default (empty) SemanticTokenRules so a missing asset degrades gracefully

When it happens

Trigger: Thrown at crates/languages/src/cpp.rs:5 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zed-industries/zed@f4178619ac (2026-08-20). Data as JSON: /api/errors/72d3c93d3671416e. Report an issue: GitHub.