{"record":{"id":"9c20509e4ae65cc6","repo":"zellij-org/zellij","slug":"rustc-didn-t-output-the-host-triple","errorCode":null,"errorMessage":"rustc didn't output the 'host' triple","messagePattern":"rustc didn't output the 'host' triple","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"xtask/src/test.rs","lineNumber":110,"sourceCode":"pub fn host_target_triple(sh: &Shell) -> anyhow::Result<String> {\n    let rustc_ver = cmd!(sh, \"rustc -vV\")\n        .read()\n        .context(\"Failed to determine host triple\")?;\n    let maybe_triple = rustc_ver\n        .lines()\n        .filter_map(|line| {\n            if !line.starts_with(\"host\") {\n                return None;\n            }\n            if let Some((_, triple)) = line.split_once(\": \") {\n                Some(triple.to_string())\n            } else {\n                None\n            }\n        })\n        .collect::<Vec<String>>();\n    match maybe_triple.len() {\n        0 => Err(anyhow!(\"rustc didn't output the 'host' triple\")),\n        1 => Ok(maybe_triple.into_iter().next().unwrap()),\n        _ => Err(anyhow!(\n            \"rustc provided multiple host triples: {:?}\",\n            maybe_triple\n        )),\n    }\n}\n","sourceCodeStart":92,"sourceCodeEnd":118,"githubUrl":"https://github.com/zellij-org/zellij/blob/98a0837077492d53dd252ab30bc3e43e41e504f4/xtask/src/test.rs#L92-L118","documentation":"host_target_triple runs `rustc -vV` and parses lines starting with 'host' via split_once(\": \"), expecting exactly one host triple. If no parsable host line is found, the environment's rustc did not report a host triple in the expected format and test setup aborts.","triggerScenarios":"A rustc shim/wrapper (RUSTC_WRAPPER, toolchain managers) that alters or drops `rustc -vV` output; a broken or partially installed toolchain; PATH resolving `rustc` to something that is not the real compiler.","commonSituations":"CI images with custom RUSTC env vars; unusual rustup states after partial updates; sandboxes where rustc's stderr/stdout is redirected.","solutions":["Run `rustc -vV` yourself and confirm a `host: <triple>` line is present","Unset overrides (`RUSTC`, `RUSTC_WRAPPER`) and retry","Repair the toolchain: `rustup update` or reinstall the active toolchain","If a wrapper is required, make it pass `rustc -vV` through unchanged"],"exampleFix":"# before: wrapper mangles rustc -vV\nRUSTC_WRAPPER=./my-wrapper cargo xtask test\n\n# after\nunset RUSTC_WRAPPER\ncargo xtask test","handlingStrategy":"validation","validationCode":"# confirm rustc reports a host triple before running test tasks\nrustc -vV | grep -E '^host: [^ ]+' >/dev/null || {\n  echo 'rustc did not report a host triple; check RUSTC/RUSTC_WRAPPER and toolchain'; exit 1;\n}","typeGuard":"fn parse_host_triple(rustc_vv: &str) -> Option<&str> {\n    let mut hits = rustc_vv.lines().filter_map(|l| l.starts_with(\"host\").then(|| l.split_once(\": \")).flatten().map(|(_, t)| t));\n    let first = hits.next()?;\n    hits.next().is_none().then_some(first)\n}","tryCatchPattern":"match test::host_target_triple(&sh) {\n    Ok(triple) => { /* proceed */ }\n    Err(e) if e.to_string().contains(\"rustc didn't output the 'host' triple\") => {\n        // diagnose toolchain: print `rustc -vV`, unset RUSTC_WRAPPER, then retry once\n    }\n    Err(e) => return Err(e),\n}","preventionTips":["Keep RUSTC and RUSTC_WRAPPER unset for tasks that only query the toolchain","Smoke-test new CI images with `rustc -vV | grep '^host: '`","Repair partial toolchains with rustup update before running xtask test"],"tags":["rustc","toolchain","environment","test"],"backgroundTag":null,"analyzedSha":"98a0837077492d53dd252ab30bc3e43e41e504f4","analyzedAt":"2026-08-16T13:02:01.396Z","schemaVersion":2},"datasetVersion":"2026-08-16T13:17:31.715Z"}