What causes "Invalid env-var format '{}': expected KEY=VALUE" in Kuberwastaken/claurst?

Rewrite the entry as KEY=VALUE (e.g. "DEBUG=1" instead of "DEBUG").

Invalid env-var format

Error message

Invalid env-var format '{}': expected KEY=VALUE

What it means

Thrown by `parse_env_vars` in src-rust/crates/core/src/feature_gates.rs when an entry in the input list contains no `=` character, so it cannot be split into KEY and VALUE. The parser requires every entry to be in KEY=VALUE form and fails fast on the first malformed entry.

Solutions

Rewrite the entry as KEY=VALUE (e.g. "DEBUG=1" instead of "DEBUG").
If the intent is only to assert an env var exists, use "KEY=1" or any placeholder value.
Trim the input list to remove empty strings caused by trailing separators.
Validate entries with `entry.contains('=')` before passing them to the parser.

Example fix

// before
parse_env_vars(&["DEBUG", "RUST_LOG=info"])?;

// after
parse_env_vars(&["DEBUG=1", "RUST_LOG=info"])?;

Defensive patterns

Strategy: validation

Validate before calling

fn valid_env_entries(entries: &[String]) -> bool {
    entries.iter().all(|e| !e.is_empty() && e.contains('='))
}

Type guard

fn as_key_value(entry: &str) -> Option<(&str, &str)> {
    let pos = entry.find('=')?;
    Some((&entry[..pos], &entry[pos + 1..]))
}

Try / catch

match parse_env_vars(&entries) {
    Ok(map) => use(map),
    Err(e) if e.to_string().contains("Invalid env-var format") => {
        // surface which entry was malformed to the user
        report_bad_entry(&entries, &e);
    }
    Err(e) => return Err(e),
}

Prevention

Always write env entries as KEY=VALUE, even for existence checks (KEY=1).
Trim lists and drop empty strings before parsing.
Validate entries with entry.contains('=') at config-load time.
Never mix bare variable names with KEY=VALUE pairs in one list.

When it happens

Trigger: Passing a bare variable name without `=` (e.g. "DEBUG") or an empty/whitespace-only string to parse_env_vars; callers like parse_env_vars_basic forward user-supplied gate config entries verbatim.

Common situations: Config listing env var names to check for existence but written without `=VALUE`; copy-pasted settings where `=` was lost; YAML/TOML lists mixing names and KEY=VALUE pairs; trailing empty string from a split on ',' with a trailing comma.

Understand the failure class

Background: "is not a valid" / "Invalid ... value" environment variable errors: how libraries validate env vars and what to do when they reject yours — this error's family across 48 libraries.

Related errors

AI-assisted analysis of Kuberwastaken/claurst@b0637c97ec (2026-09-10). Data as JSON: /api/errors/7f1c2fb7118e05ed. Report an issue: GitHub.

Appendix: source

Thrown at src-rust/crates/core/src/feature_gates.rs:131

    }
}

// ---------------------------------------------------------------------------
// Env-var parsing for --env KEY=VALUE arguments
// ---------------------------------------------------------------------------

/// Parse a slice of `"KEY=VALUE"` strings into a `HashMap`.
///
/// Returns an error if any entry lacks a `=` separator.
pub fn parse_env_vars(args: &[String]) -> anyhow::Result<HashMap<String, String>> {
    let mut map = HashMap::new();
    for entry in args {
        if let Some(pos) = entry.find('=') {
            let key = entry[..pos].to_string();
            let value = entry[pos + 1..].to_string();
            map.insert(key, value);
        } else {
            return Err(anyhow::anyhow!(
                "Invalid env-var format '{}': expected KEY=VALUE",
                entry
            ));
        }
    }
    Ok(map)
}

// ---------------------------------------------------------------------------
// AWS region
// ---------------------------------------------------------------------------

/// Resolve the AWS region, checking `AWS_REGION` then `AWS_DEFAULT_REGION`,
/// falling back to `"us-east-1"`.
pub fn get_aws_region() -> String {
    std::env::var("AWS_REGION")
        .or_else(|_| std::env::var("AWS_DEFAULT_REGION"))
        .unwrap_or_else(|_| "us-east-1".to_string())

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