{"record":{"id":"0a76c32dc14358c1","repo":"tauri-apps/tauri","slug":"could-not-find-target-arch-when-running-rustc","errorCode":null,"errorMessage":"could not find `target_arch` when running `rustc --print cfg`.","messagePattern":"could not find `target_arch` when running `rustc --print cfg`\\.","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/tauri-bundler/src/bundle/platform.rs","lineNumber":46,"sourceCode":"  RustCfg { target_arch }\n}\n\n/// Try to determine the current target triple.\n///\n/// Returns a target triple (e.g. `x86_64-unknown-linux-gnu` or `i686-pc-windows-msvc`) or an\n/// `Error::Config` if the current config cannot be determined or is not some combination of the\n/// following values:\n/// `linux, mac, windows` -- `i686, x86, armv7` -- `gnu, musl, msvc`\n///\n/// * Errors:\n///     * Unexpected system config\npub fn target_triple() -> Result<String, crate::Error> {\n  let arch_res = Command::new(\"rustc\").args([\"--print\", \"cfg\"]).output_ok();\n\n  let arch = match arch_res {\n    Ok(output) => parse_rust_cfg(String::from_utf8_lossy(&output.stdout).into())\n      .target_arch\n      .expect(\"could not find `target_arch` when running `rustc --print cfg`.\"),\n    Err(err) => {\n      log::warn!(\n      \"failed to determine target arch using rustc, error: `{}`. The fallback is the architecture of the machine that compiled this crate.\",\n      err,\n    );\n      if cfg!(target_arch = \"x86\") {\n        \"i686\".into()\n      } else if cfg!(target_arch = \"x86_64\") {\n        \"x86_64\".into()\n      } else if cfg!(target_arch = \"arm\") {\n        \"armv7\".into()\n      } else if cfg!(target_arch = \"aarch64\") {\n        \"aarch64\".into()\n      } else if cfg!(target_arch = \"riscv64\") {\n        \"riscv64\".into()\n      } else {\n        return Err(crate::Error::ArchError(String::from(\n          \"Unable to determine target-architecture\",","sourceCodeStart":28,"sourceCodeEnd":64,"githubUrl":"https://github.com/tauri-apps/tauri/blob/52e4b6e71d8632a7e648f866c442e287ecddee34/crates/tauri-bundler/src/bundle/platform.rs#L28-L64","documentation":"To derive the default target triple, the bundler runs rustc --print cfg and parses the target_arch line. The expect fires only when the command executed successfully but its stdout contains no target_arch assignment — i.e. the rustc on PATH is not behaving like a standard rustc. A command that fails outright takes the documented fallback to the compile-time architecture instead.","triggerScenarios":"A RUSTC wrapper (RUSTC_WRAPPER such as an sccache variant, Nix/rustup shim) that swallows or rewrites --print cfg output; a rustup proxy misconfiguration; a toolchain so old it omits target_arch from --print cfg.","commonSituations":"CI with RUSTC_WRAPPER set; dev containers where rustc is a wrapper script; broken or partial rustup installs; environments overriding the RUSTC variable.","solutions":["Run rustc --print cfg | grep target_arch in the same shell — it must print a target_arch line; fix or bypass whatever wrapper breaks it","Unset RUSTC_WRAPPER (or make the wrapper pass --print cfg through) and retry the bundle","Repair the toolchain: rustup update / rustup default stable, or reinstall rustup if the proxy is broken","Pass an explicit target (tauri build --target <triple>) so the bundler does not have to infer the arch from rustc output"],"exampleFix":"# before — wrapper breaks cfg printing\nRUSTC_WRAPPER=sccache tauri build\n\n# after — bypass the wrapper for the bundling run\nenv -u RUSTC_WRAPPER tauri build --target x86_64-unknown-linux-gnu","handlingStrategy":"validation","validationCode":"# preflight: the rustc on PATH must report target_arch\nrustc --print cfg | grep -q '^target_arch=' || { echo 'rustc shim does not report target_arch — fix toolchain/wrapper'; exit 1; }","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Do not let RUSTC_WRAPPER intercept --print cfg in bundling jobs; bypass it for bundle runs","Pin the toolchain with rustup on CI and assert rustc --print cfg output in a preflight step","Pass --target explicitly to tauri build so arch inference from rustc is unnecessary"],"tags":["rustc","toolchain","target-triple","env","tauri-bundler"],"backgroundTag":"toolchain-detection-failure","analyzedSha":"52e4b6e71d8632a7e648f866c442e287ecddee34","analyzedAt":"2026-08-20T13:59:20.734Z","schemaVersion":2},"datasetVersion":"2026-08-31T22:30:34.772Z"}