{"record":{"id":"6bf1bbcc6b908475","repo":"cross-rs/cross","slug":"could-not-get-username","errorCode":null,"errorMessage":"Could not get UserName.","messagePattern":"Could not get UserName\\.","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/id.rs","lineNumber":48,"sourceCode":"\n#[cfg(target_os = \"windows\")]\npub fn username() -> Result<Option<String>> {\n    use std::ptr;\n\n    use winapi::um::winbase::GetUserNameW;\n\n    unsafe {\n        let mut size = 0;\n        GetUserNameW(ptr::null_mut(), &mut size);\n\n        if size == 0 {\n            return Ok(None);\n        }\n\n        let mut username = Vec::with_capacity(size as usize);\n\n        if GetUserNameW(username.as_mut_ptr(), &mut size) == 0 {\n            eyre::bail!(\"Could not get UserName.\");\n        }\n\n        // Remove null terminator.\n        username.set_len((size - 1) as usize);\n\n        Ok(Some(String::from_utf16_lossy(&username)))\n    }\n}\n\n#[cfg(not(target_os = \"windows\"))]\npub fn username() -> Result<Option<String>> {\n    let name = unsafe {\n        Errno::clear();\n\n        let passwd = libc::getpwuid(Uid::current().as_raw());\n\n        if passwd.is_null() {\n            let errno = Errno::last_raw();","sourceCodeStart":30,"sourceCodeEnd":66,"githubUrl":"https://github.com/cross-rs/cross/blob/8c1a8aa4b661711f4b7b6ac07c2e8929ce2f7d27/src/id.rs#L30-L66","documentation":"This error is thrown by the Windows `username()` helper when the Win32 API `GetUserNameW` fails (returns 0). The function queries the current user's login name for toolchain/directory identification and converts it to a Rust String; failure means Windows refused the credential query. The error aborts the lookup rather than guessing a fallback name.","triggerScenarios":"Calling `username()` on Windows when `GetUserNameW` returns 0 — e.g. when no user token is associated with the process (service session, broken profile, extremely small buffer) or the API call is otherwise rejected.","commonSituations":"Running under a Windows service or scheduled task with no interactive user; corrupted user profile where the access token has no username; running in restricted sandboxes/CI containers that strip user context.","solutions":["Verify the process runs under a real user session (not an empty-token service/impersonation context).","Check Windows event logs / `whoami` in the same context to confirm the OS can resolve the username.","If username is unavailable by design, prefer the `Ok(None)` code path (before this call) instead of forcing the lookup.","Retry in an environment with a loaded user profile (e.g. interactive logon, `psexec -i`, or configured service account with profile)."],"exampleFix":"// before\nlet name = username()?; // bails with \"Could not get UserName.\"\n// after\nlet name = match username() {\n    Ok(Some(n)) => n,\n    Ok(None) => fallback_default_name(),\n    Err(e) => fallback_default_name(), // use a default dir name instead of failing\n};","handlingStrategy":"fallback","validationCode":"#[cfg(windows)]\nfn can_query_username() -> bool {\n    // username() returns Ok(None) *before* GetUserNameW is tried when\n    // the buffer size query fails, so only a real call failure hits the error.\n    std::env::var(\"USERNAME\").is_ok() || whoami_check()\n}","typeGuard":"fn has_user_context() -> bool {\n    std::env::var(\"USERNAME\").is_ok()\n}","tryCatchPattern":null,"preventionTips":["Prefer treating username as Option and provide a fallback directory/toolchain name.","Avoid running the lookup in service/CI sessions without an interactive user token.","Log the OS error code from GetLastError to distinguish profile corruption from sandbox restrictions."],"tags":["windows","winapi","username","environment"],"backgroundTag":"missing-env-var","analyzedSha":"8c1a8aa4b661711f4b7b6ac07c2e8929ce2f7d27","analyzedAt":"2026-09-13T15:10:43.988Z","contentChangedAt":"2026-09-13T15:10:43.988Z","schemaVersion":2},"datasetVersion":"2026-09-16T09:17:16.951Z"}