wasmerio/wasmer · error · anyhow::Error

Cannot create app from template in offline mode

Error message

Cannot create app from template in offline mode

What it means

create_from_template requires a WasmerClient because templates are fetched from the registry. When the client is None (offline mode / not connected), it bails with 'Cannot create app from template in offline mode'. The library throws it since remote template download is impossible without a connection.

Source

Thrown at lib/cli/src/commands/app/create.rs:653

            let mut path_root_dir = PathBuf::from(root_dir);
            if path_root_dir.is_absolute() {
                path_root_dir = path_root_dir.strip_prefix("/")?.to_path_buf();
            }
            return Ok((url, Some(path_root_dir)));
        }

        Ok((url, None))
    }

    async fn create_from_template(
        &self,
        client: Option<&WasmerClient>,
        owner: &str,
        app_name: &str,
    ) -> anyhow::Result<bool> {
        let client = match client {
            Some(client) => client,
            None => anyhow::bail!("Cannot create app from template in offline mode"),
        };

        let (url, mut root_dir) = self.get_template_url(client).await?;
        root_dir = root_dir.map(|v| v.clean());
        let root_dir_str = if let Some(ref root_dir) = root_dir {
            root_dir.display().to_string()
        } else {
            "./".to_string()
        };
        tracing::info!("Downloading template from url {url}, using root dir {root_dir_str}");

        let output_path = self.get_output_dir(app_name).await?;
        let pb = indicatif::ProgressBar::new_spinner();

        pb.enable_steady_tick(std::time::Duration::from_millis(500));
        pb.set_style(
            indicatif::ProgressStyle::with_template("{spinner:.magenta} {msg}")
                .unwrap()

View on GitHub (pinned to 8c4b9ee9d3)

Solutions

1. Remove the --offline flag and ensure network access to the registry so a client can be created.
2. Log in / fix registry configuration (WASMER_REGISTRY, tokens) so a WasmerClient is available.
3. Pre-scaffold locally (e.g. --use-local-manifest or a checked-in template) instead of fetching a template while offline.

Example fix

// before
// wasmer app create --offline --template wasmer/hello-world
// after
// wasmer app create --template wasmer/hello-world

if (args.offline && args.template) {
  throw new Error('cannot fetch a registry template in offline mode');
}

fn can_fetch_templates(client: &Option<WasmerClient>) -> bool {
    client.is_some()
}

match result {
    Err(e) if e.to_string().contains("offline mode") => {
        eprintln!("retry with network access or use a local manifest");
        // fall back to --use-local-manifest flow
    }
    other => other?,
}

When it happens

Trigger: Running `wasmer app create --template <slug>` while offline (--offline flag, no network, or no registry client could be constructed), so run_async passes client: None into create_from_template.

Common situations: Air-gapped/CI environments using --offline; network outage or blocked registry host; unauthenticated setups where client resolution failed.

Related errors

• Stopping as the directory is not empty
• The --use_local_manifest flag was passed, but path {} does n
• No template selected
• No app name specified: use --name <app_name>
• No owner specified: use --owner <owner>

AI-assisted analysis of wasmerio/wasmer@8c4b9ee9d3 (2026-09-01). Data as JSON: /api/errors/495482a3061b0c76. Report an issue: GitHub.