Function is_rate_limited 

pub fn is_rate_limited(stderr: &str) -> bool

Check whether cargo publish stderr reports a registry rate-limit refusal rather than a fault that retrying cannot fix.

crates.io meters new crate names on its own schedule: a small burst allowance, then roughly one name per ten minutes. Once a workspace publishes more new names than the burst allows, every further name is refused with a deadline embedded in the message. That deadline is already longer than any exponential backoff, so a retry that ignores it only spends the budget and fails again — this is the class of failure that must wait out the deadline the registry handed back.

Arguments

• &str - cargo publish stderr output

Returns

• bool - True when the output reports a registry rate limit