NousResearch/hermes-agent · error · anyhow::Error

install script invocation failed: {e:#}

Error message

install script invocation failed: {e:#}

What it means

Raised when powershell::run_script fails to launch or stream the resolved install-main.ps1 script. This is the wrapper error for the entire PowerShell child-process lifecycle: spawning powershell.exe, passing the HERMES_HOME override, streaming stdout/stderr to the log sink, or the cancellation channel aborting. The lower-level cause is chained via {e:#} (anyhow display with chain).

Source

Thrown at apps/bootstrap-installer/src-tauri/src/bootstrap.rs:922

                    stream: LogStream::Stderr,
                },
            );
            // stderr-level lines get warn! so they're visually distinct
            // when scrolling through the log later.
            match &stage_for_stderr_log {
                Some(name) => {
                    tracing::warn!(target: "bootstrap.log", stage = %name, "stderr: {line}")
                }
                None => tracing::warn!(target: "bootstrap.log", "stderr: {line}"),
            }
        }),
    };

    powershell::run_script(script_path, args, sink, hermes_home_override, cancel_rx)
        .await
        .map_err(|e| {
            tracing::error!(?e, "install script invocation failed");
            anyhow!("install script invocation failed: {e:#}")
        })
}

fn build_pin_args(script: &install_script::ResolvedScript) -> Vec<String> {
    let mut out = Vec::new();
    if let Some(c) = &script.commit {
        out.push("-Commit".to_string());
        out.push(c.clone());
    }
    if let Some(b) = &script.branch {
        out.push("-Branch".to_string());
        out.push(b.clone());
    }
    out
}

fn emit_event(app: &AppHandle, event: BootstrapEvent) {
    // Tee important state transitions to the rolling installer log so

View on GitHub (pinned to c896c09c42)

Solutions

  1. Read the chained error {e:#} — it distinguishes spawn failure from cancellation from script failure.
  2. Verify powershell.exe launches: run `powershell -ExecutionPolicy Bypass -File <script>` manually from a terminal.
  3. Check the streamed stderr lines already logged under the `bootstrap.log` target — the actual script error is usually there, not in this wrapper message.
  4. If corporate policy blocks unsigned scripts, exempt HERMES_HOME or run from an unrestricted context.
Defensive patterns

Strategy: try-catch

Validate before calling

// Pre-flight: powershell must exist and scripts must be runnable.
fn powershell_available() -> bool {
    std::process::Command::new("powershell")
        .args(["-NoProfile", "-Command", "exit 0"])
        .output()
        .map(|o| o.status.success())
        .unwrap_or(false)
}

if !powershell_available() {
    eprintln!("PowerShell is unavailable or blocked by policy — install cannot proceed.");
}

Try / catch

if let Err(e) = powershell::run_script(script_path, args, sink, override_home, cancel_rx).await {
    let chain = format!("{e:#}");
    if chain.contains("cancel") {
        // user-initiated: exit quietly, not an error
        return Ok(());
    }
    tracing::error!(?e, "install script invocation failed");
    return Err(anyhow!("install script invocation failed: {e:#}"));
}

Prevention

When it happens

Trigger: powershell.exe missing from PATH or blocked by policy (Constrained Language Mode / AppLocker); spawning the child fails (exec format, permission); the cancel_rx channel fires because the user cancelled; the script path does not exist at invocation time; HERMES_HOME override points to an unusable directory.

Common situations: Corporate Windows machines with PowerShell execution policy set to AllSigned or aAppLocker rules blocking unsigned scripts; PATH mangled so powershell.exe is not found; user clicks Cancel in the installer UI mid-script; antivirus quarantining install-main.ps1 before it runs.

Related errors

AI-assisted analysis of NousResearch/hermes-agent@c896c09c42 (2026-08-14). Data as JSON: /api/errors/e48664d7ff302b10. Report an issue: GitHub.