Invalid environment variable format: '{pair}'. Environment v

Error message

Invalid environment variable format: '{pair}'. Environment variables should be added as: -e KEY1=value1 -e KEY2=value2

What it means

`parse_env_vars` requires every -e value to be a KEY=value pair with a non-empty key. Any pair lacking an `=` or with an empty key is rejected with this message, which restates the correct per-flag syntax.

Source

Thrown at crates/codegen/xai-grok-pager/src/mcp_cmd.rs:442

        || !name
            .chars()
            .all(|c| c.is_ascii_alphanumeric() || c == '-' || c == '_')
    {
        bail!(
            "Invalid name '{name}'. Names can only contain letters, numbers, hyphens, and underscores."
        );
    }
    Ok(())
}

fn parse_env_vars(pairs: &[String]) -> Result<HashMap<String, String>> {
    let mut env = HashMap::new();
    for pair in pairs {
        match pair.split_once('=') {
            Some((key, value)) if !key.is_empty() => {
                env.insert(key.to_string(), value.to_string());
            }
            _ => bail!(
                "Invalid environment variable format: '{pair}'. Environment variables should be added as: -e KEY1=value1 -e KEY2=value2"
            ),
        }
    }
    Ok(env)
}

fn parse_headers(headers: &[String]) -> Result<HashMap<String, String>> {
    let mut parsed = HashMap::new();
    for header in headers {
        let Some((name, value)) = header.split_once(':') else {
            bail!("Invalid header format: '{header}'. Expected format: 'Name: value'");
        };
        let name = name.trim();
        if name.is_empty() {
            bail!("Invalid header: '{header}'. Header name cannot be empty.");
        }
        parsed.insert(name.to_string(), value.trim().to_string());

View on GitHub (pinned to bc7f02eddd)

Solutions

Quote each pair: -e "KEY=value with spaces".
Use one -e flag per variable: -e A=1 -e B=2.
Ensure each pair contains '=' with a non-empty key before the equals sign.

Example fix

// before
grok mcp add fs -e LOG_LEVEL -- npx server-fs
// after
grok mcp add fs -e LOG_LEVEL=debug -- npx server-fs

Defensive patterns

Strategy: validation

Validate before calling

for pair in env_pairs {
    match pair.split_once('=') {
        Some((k, _)) if !k.is_empty() => {}
        _ => panic!("'{pair}' is not KEY=value; use one -e flag per variable"),
    }
}

Prevention

Quote values containing spaces.
One -e flag per variable, always with KEY=value.
Never pass bare variable names to -e.

When it happens

Trigger: `-e KEY` (no =value), `-e =value` (empty key), or an unquoted value containing spaces that split into multiple args like `-e KEY=hello world`.

Common situations: Shell splitting of unquoted values with spaces, assuming -e is greedy and accepts multiple pairs (`-e A=1 B=2`), passing bare variable names expecting the parent environment to be forwarded.

Related errors

AI-assisted analysis of xai-org/grok-build@bc7f02eddd (2026-08-31). Data as JSON: /api/errors/b6898bf7006fa83e. Report an issue: GitHub.