{"record":{"id":"e040e154d85fb96a","repo":"bevyengine/bevy","slug":"failed-to-write-registration-function-export-name","errorCode":null,"errorMessage":"Failed to write registration function {export_name}","messagePattern":"Failed to write registration function (.+?)","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/bevy_reflect/derive/src/impls/common.rs","lineNumber":229,"sourceCode":"                .recursive(true)\n                .create(&path)\n                .unwrap_or_else(|_| panic!(\"Failed to create {path:?}\"));\n            let file_path = path.join(env::var(\"CARGO_CRATE_NAME\").unwrap());\n            let file = fs::OpenOptions::new()\n                .create(true)\n                .write(true)\n                .truncate(true)\n                .open(&file_path)\n                .unwrap_or_else(|_| panic!(\"Failed to create {file_path:?}\"));\n            Mutex::new(file)\n        });\n\n        let export_name = format!(\"_bevy_reflect_register_{}\", uuid::Uuid::new_v4().as_u128());\n\n        {\n            let mut file = REGISTRATION_FNS_EXPORT.lock().unwrap();\n            writeln!(file, \"{export_name}\")\n                .unwrap_or_else(|_| panic!(\"Failed to write registration function {export_name}\"));\n            // We must sync_data to ensure all content is written before releasing the lock.\n            file.sync_data().unwrap();\n        };\n\n        Some(quote! {\n            /// # Safety\n            /// This function must only be used by the `load_type_registrations` macro.\n            #[unsafe(export_name=#export_name)]\n            pub unsafe extern \"Rust\" fn bevy_register_type(registry: &mut #bevy_reflect_path::TypeRegistry) {\n                <#type_path as #bevy_reflect_path::__macro_exports::RegisterForReflection>::__register(registry);\n            }\n        })\n    }\n\n    #[cfg(all(\n        feature = \"auto_register_inventory\",\n        not(feature = \"auto_register_static\")\n    ))]","sourceCodeStart":211,"sourceCodeEnd":247,"githubUrl":"https://github.com/bevyengine/bevy/blob/396ca727080776bd313bb892423b7d94e03b81b4/crates/bevy_reflect/derive/src/impls/common.rs#L211-L247","documentation":"Panic during auto-registration: writing the generated registration function for the export (named by UUID) to the crate's registration file failed. Usually an I/O or permission issue in the build directory during compilation.","triggerScenarios":"Thrown at crates/bevy_reflect/derive/src/impls/common.rs:229 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Check disk space and filesystem permissions","Clean the target directory and rebuild","Remove stale scratch files from interrupted builds"],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"396ca727080776bd313bb892423b7d94e03b81b4","analyzedAt":"2026-08-20T16:12:39.808Z","contentChangedAt":"2026-08-20T16:12:39.808Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}