{"record":{"id":"ba695a075e2efa5d","repo":"slint-ui/slint","slug":"could-not-generate-the-d8-command-e","errorCode":null,"errorMessage":"Could not generate the D8 command: {e}","messagePattern":"Could not generate the D8 command: (.+?)","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"internal/backends/android-activity/build.rs","lineNumber":67,"sourceCode":"        .unwrap_or_else(|e| panic!(\"Could not generate the java compiler command: {e}\"))\n        .args([\"-encoding\", \"UTF-8\"])\n        .output()\n        .unwrap_or_else(|e| panic!(\"Could not run the java compiler: {e}\"));\n\n    if !o.status.success() {\n        panic!(\"Java compilation failed: {}\", String::from_utf8_lossy(&o.stderr));\n    }\n\n    let o = Dexer::new()\n        .android_jar(&android_jar)\n        .class_path(&out_class_dir)\n        .collect_classes(&out_class_dir)\n        .unwrap()\n        .release(release_mode)\n        .android_min_api(20) // disable multidex for single dex file output\n        .out_dir(out_dir)\n        .command()\n        .unwrap_or_else(|e| panic!(\"Could not generate the D8 command: {e}\"))\n        .output()\n        .unwrap_or_else(|e| panic!(\"Error running D8: {e}\"));\n\n    if !o.status.success() {\n        eprintln!(\"Dex conversion failed: {}\", String::from_utf8_lossy(&o.stderr));\n        let java_home = android_build::java_home().unwrap();\n        let java_ver = android_build::check_javac_version(&java_home).unwrap();\n        if java_ver >= 21 {\n            eprintln!(\"WARNING: JDK version 21 is known to cause an error with older android SDK\");\n            eprintln!(\"See https://github.com/slint-ui/slint/issues/4973\");\n            eprintln!(\n                \"Try downgrading your version of Java to something like JDK 17, or upgrade to the SDK build tools 35\"\n            );\n        }\n        panic!(\"Dex conversion failed\");\n    }\n\n    println!(\"cargo:rerun-if-changed={java_src_path}\");","sourceCodeStart":49,"sourceCodeEnd":85,"githubUrl":"https://github.com/slint-ui/slint/blob/bb937076de3f7919766c1f25e2e969367cf77e9a/internal/backends/android-activity/build.rs#L49-L85","documentation":"In the android-activity build script, the Dexer builds the command line for the D8 dexer tool; this panic is the command()-error handler. It means the D8 invocation could not be constructed — typically the D8 jar or android.jar path is missing/invalid in the Android SDK/NDK layout, so no command could be produced. The build for the Android Java helper cannot proceed without it.","triggerScenarios":"Thrown at internal/backends/android-activity/build.rs:67 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Inspect {e} from Dexer::command(); it typically means the Android build-tools D8/dx jar or android.jar path is missing or malformed","Verify ANDROID_NDK / android_build configuration: android_jar must point to a valid platforms/android-<api>/android.jar","Ensure build-tools are installed via sdkmanager and that the Dexer's class-path directories exist and contain .class files"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"bb937076de3f7919766c1f25e2e969367cf77e9a","analyzedAt":"2026-09-16T01:37:20.251Z","contentChangedAt":"2026-09-16T01:37:20.251Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}