What causes "Nickname {} conflicts with saved configuration for server {}: {}://{}" in clockworklabs/SpacetimeDB?

Choose a nickname that is not used as any server's nickname or host

clockworklabs/SpacetimeDB · error · anyhow::Error

Nickname conflicts with saved configuration for server : ://

Error message

Nickname {} conflicts with saved configuration for server {}: {}://{}

What it means

`spacetime server edit <server> --nickname <new>` rejects the rename because the requested nickname already resolves to a different saved server. Nicknames and hosts share one lookup namespace (`find_server`), so a nickname equal to another entry's host is also a conflict.

Solutions

Choose a nickname that is not used as any server's nickname or host
Rename or remove the conflicting server first

Example fix

# before
spacetime server edit maincloud --nickname local
# error: Nickname local conflicts with saved configuration for server ...

# after
spacetime server edit maincloud --nickname cloud-prod

Defensive patterns

Strategy: validation

Validate before calling

// ensure the candidate nickname does not resolve to another server
if let Ok(other) = config.find_server(new_nick) {
    if other.host != target.host {
        anyhow::bail!("nickname already in use by {}", other.nick_or_host());
    }
}

Try / catch

Catch the 'Nickname ... conflicts with saved configuration' bail and prompt the operator for a different nickname instead of aborting.

Prevention

Run `spacetime server list` before renaming to see taken names
Keep nicknames clearly distinct from host strings since they share a namespace

When it happens

Trigger: Calling edit_server with a new_nickname that find_server resolves to another server entry — either that server's nickname or its host.

Common situations: Renaming a server to a name already in use; trying to set a nickname that duplicates another server's host string.

Related errors

AI-assisted analysis of clockworklabs/SpacetimeDB@6dee26c6ef (2026-08-20). Data as JSON: /api/errors/c4425a7ccab0a6af. Report an issue: GitHub.

Appendix: source

Thrown at crates/cli/src/config.rs:379

    ///
    /// Implements `spacetime server edit`.
    ///
    /// Returns `Err` if no such server exists.
    /// On success, returns `(old_nickname, old_host, hold_protocol)`,
    /// with `Some` for each field that was changed.
    pub fn edit_server(
        &mut self,
        server: &str,
        new_nickname: Option<&str>,
        new_host: Option<&str>,
        new_protocol: Option<&str>,
    ) -> anyhow::Result<(Option<String>, Option<String>, Option<String>)> {
        // Check if the new nickname or host name would introduce ambiguities between
        // server configurations.
        if let Some(new_nick) = new_nickname
            && let Ok(other_server) = self.find_server(new_nick)
        {
            anyhow::bail!(
                "Nickname {} conflicts with saved configuration for server {}: {}://{}",
                new_nick,
                other_server.nick_or_host(),
                other_server.protocol,
                other_server.host
            );
        }
        if let Some(new_host) = new_host
            && let Ok(other_server) = self.find_server(new_host)
        {
            anyhow::bail!(
                "Host {} conflicts with saved configuration for server {}: {}://{}",
                new_host,
                other_server.nick_or_host(),
                other_server.protocol,
                other_server.host
            );
        }

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