clockworklabs/SpacetimeDB · error · anyhow::Error

`--module-path` cannot be used when `spacetime.json`…

Error message

`--module-path` cannot be used when `spacetime.json` contains publish targets. Remove `--module-path` or run without publish targets in config.

What it means

`spacetime dev` refuses to combine a CLI-provided --module-path with a spacetime.json that declares publish targets: with multiple publish targets there is no single module path, so the flag would be ambiguous. Only a flag whose value source is the command line triggers the check; config-provided paths are fine.

Solutions

1. Drop --module-path and let the publish targets drive the module paths
2. Remove the publish targets from spacetime.json if you truly want the single-path workflow
3. Set module paths per target inside spacetime.json

Example fix

# before
spacetime dev --module-path ./spacetimedb
# spacetime.json has "publish": [ ... ]

# after
spacetime dev    # module paths come from the publish targets

// skip the flag when publish targets exist in spacetime.json
let has_publish_targets = !spacetime_json.publish.as_ref().map_or(false, Vec::is_empty);
if has_publish_targets {
    assert!(!cli_has_flag("--module-path"), "remove --module-path; publish targets own module paths");
}

When it happens

Trigger: spacetime.json contains a non-empty publish array and the command line includes --module-path (ValueSource::CommandLine).

Common situations: Converting a legacy single-module project whose scripts pass --module-path to the multi-target spacetime.json format; leftover flags in shell aliases or Makefiles.

Related errors

• Aborted.
• Cannot continue without a module path.
• Cannot use module-specific arguments
• database is a required field in publish config
• Missing loaded config directory

AI-assisted analysis of clockworklabs/SpacetimeDB@3653d2ed49 (2026-08-20). Data as JSON: /api/errors/f157785b20f21385. Report an issue: GitHub.

Appendix: source

Thrown at crates/cli/src/subcommands/dev.rs:330

    }

    let spacetime_config = loaded_config.as_ref().map(|lc| &lc.config);
    // A config has publish targets if it has a "database" field or children
    let has_publish_targets_in_config = spacetime_config
        .map(|c| c.additional_fields.contains_key("database") || c.children.is_some())
        .unwrap_or(false);
    let has_generate_targets_in_config = spacetime_config
        .and_then(|c| c.generate.as_ref())
        .map(|g| !g.is_empty())
        .unwrap_or(false);

    let module_path_from_cli_flag = args.value_source("module-path") == Some(ValueSource::CommandLine);
    let project_path_from_cli_flag = args.value_source("project-path") == Some(ValueSource::CommandLine);
    let module_bindings_path_from_cli_flag =
        args.value_source("module-bindings-path") == Some(ValueSource::CommandLine);

    if has_publish_targets_in_config && module_path_from_cli_flag {
        anyhow::bail!(
            "`--module-path` cannot be used when `spacetime.json` contains publish targets. \
             Remove `--module-path` or run without publish targets in config."
        );
    }

    if has_generate_targets_in_config
        && (module_path_from_cli_flag || project_path_from_cli_flag || module_bindings_path_from_cli_flag)
    {
        anyhow::bail!(
            "`--module-path`, `--project-path`, and `--module-bindings-path` cannot be used when \
             `spacetime.json` contains generate targets. Remove these flags or remove generate targets from config."
        );
    }

    // Fetch the database name if it was passed through a CLI arg
    let database_name_from_cli: Option<String> = args
        .get_one::<String>("database")
        .or_else(|| args.get_one::<String>("database-flag"))

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