diff --git a/apps/bootstrap-installer/src-tauri/src/update.rs b/apps/bootstrap-installer/src-tauri/src/update.rs
index 28597600e505..6746600bb275 100644
--- a/apps/bootstrap-installer/src-tauri/src/update.rs
+++ b/apps/bootstrap-installer/src-tauri/src/update.rs
@@ -733,6 +733,13 @@ fn update_child_env(install_root: &Path) -> Vec<(String, OsString)> {
         "HERMES_HOME".to_string(),
         hermes_home.as_os_str().to_os_string(),
     )];
+    // `hermes update` is a Python CLI writing to a pipe here, so CPython
+    // block-buffers its stdout: nothing reaches run_streamed (and the live
+    // log UI) until 8 KB accumulate or the process exits. Long quiet steps —
+    // the pre-update backup can zip multi-GB archives for minutes — render as
+    // a frozen stage, and users cancel a healthy update. Force line-by-line
+    // output instead.
+    envs.push(("PYTHONUNBUFFERED".to_string(), OsString::from("1")));
     if let Some(path) = path_with_prepended_entries(&[
         hermes_home.join("node").join("bin"),
         venv_bin_dir(install_root),
@@ -1046,6 +1053,16 @@ mod tests {
         assert!(!is_locked(Path::new("/nonexistent/does/not/exist/xyz")));
     }
 
+    #[test]
+    fn update_child_env_forces_unbuffered_python() {
+        let envs = update_child_env(Path::new("/x/hermes-agent"));
+        assert!(
+            envs.iter()
+                .any(|(k, v)| k == "PYTHONUNBUFFERED" && v.to_str() == Some("1")),
+            "update children must run unbuffered so long steps stream to the live log"
+        );
+    }
+
     #[test]
     fn lock_probe_paths_include_desktop_app_payload() {
         let root = Path::new("/x/hermes-agent");
@@ -1056,7 +1073,12 @@ mod tests {
             "venv shim remains part of the update lock probe"
         );
         assert!(
-            probes.iter().any(|p| p.ends_with(Path::new("resources/app.asar"))),
+            // Windows/Linux payloads live under `resources/`, the macOS bundle
+            // under `Contents/Resources/` — Path::ends_with is case-sensitive.
+            probes.iter().any(|p| {
+                p.ends_with(Path::new("resources/app.asar"))
+                    || p.ends_with(Path::new("Resources/app.asar"))
+            }),
             "packaged app.asar must be probed so repair/re-clone waits for the old desktop to exit"
         );
     }
diff --git a/apps/desktop/electron/main.ts b/apps/desktop/electron/main.ts
index af25ae7712ab..750fa11489a0 100644
--- a/apps/desktop/electron/main.ts
+++ b/apps/desktop/electron/main.ts
@@ -2715,8 +2715,13 @@ async function applyUpdatesPosixInApp(opts: any) {
   // Put the Hermes-managed Node and the venv on PATH so `hermes desktop`'s
   // npm build can find them on a machine with no system Node. Windows portable
   // Node lives directly under %LOCALAPPDATA%\hermes\node, not node\bin.
+  // PYTHONUNBUFFERED: `hermes update` writes to a pipe here, so CPython
+  // block-buffers stdout and long quiet steps (the pre-update backup can zip
+  // multi-GB archives for minutes) stream nothing to the progress UI — users
+  // read the silence as a hang and cancel a healthy update.
   const env: Record<string, string> = {
     HERMES_HOME,
+    PYTHONUNBUFFERED: '1',
     PATH: pathWithHermesManagedNode(path.join(updateRoot, 'venv', 'bin'))
   }