diff --git a/.github/workflows/studio-tauri-smoke.yml b/.github/workflows/studio-tauri-smoke.yml
index 8e26b9fd0c..c6dad07f37 100644
--- a/.github/workflows/studio-tauri-smoke.yml
+++ b/.github/workflows/studio-tauri-smoke.yml
@@ -91,6 +91,16 @@ jobs:
           npm run build
           test -f dist/index.html
 
+      # The crate carries ~100 unit tests (native_file_dialogs, preflight,
+      # install, desktop_auth, ...) that nothing ran until now: this workflow
+      # only ever built. Run them here, where the toolchain and the WebKit dev
+      # packages are already installed, so a broken assertion fails the PR
+      # instead of sitting unnoticed. `--no-fail-fast` reports every failing
+      # test in one run rather than stopping at the first.
+      - name: Rust unit tests (studio/src-tauri)
+        working-directory: studio/src-tauri
+        run: cargo test --no-fail-fast
+
       - name: Tauri debug build (Linux, no bundle, no codesign)
         # `--debug` + `--no-bundle` keeps this lean: compiles the Rust crate,
         # confirms the frontend dist is wired into Tauri, but skips the AppImage
diff --git a/studio/src-tauri/src/native_file_dialogs.rs b/studio/src-tauri/src/native_file_dialogs.rs
index 0b46f81f49..4ad0e5023e 100644
--- a/studio/src-tauri/src/native_file_dialogs.rs
+++ b/studio/src-tauri/src/native_file_dialogs.rs
@@ -335,7 +335,13 @@ mod tests {
         let path = std::env::temp_dir().join(OsString::from_vec(vec![
             b'u', b'n', b's', b'l', b'o', b't', b'h', 0xff, b'.', b'c', b's', b'v',
         ]));
-        fs::write(&path, "role,content\nuser,hello\n").unwrap();
+        // Linux happily stores arbitrary bytes in a filename, but macOS enforces
+        // UTF-8 on APFS/HFS+ and rejects this name outright. The name-recovery
+        // path being asserted here is only reachable where such a file can
+        // exist, so skip rather than fail on filesystems that forbid it.
+        if fs::write(&path, "role,content\nuser,hello\n").is_err() {
+            return;
+        }
         let imported = read_selected_import(Some(path.clone())).unwrap().unwrap();
         assert_eq!(imported.name, "chat-import.csv");
         let _ = fs::remove_file(path);
diff --git a/studio/src-tauri/src/preflight/managed.rs b/studio/src-tauri/src/preflight/managed.rs
index 0d67a1c3e6..276ca05f5f 100644
--- a/studio/src-tauri/src/preflight/managed.rs
+++ b/studio/src-tauri/src/preflight/managed.rs
@@ -704,7 +704,15 @@ mod tests {
         fs::write(venv.join("pyvenv.cfg"), "home = /usr/bin\n").unwrap();
         fs::write(venv.join("unsloth_install_manifest.json"), "{}").unwrap();
 
-        let site_packages = venv.join("lib").join("python3.11").join("site-packages");
+        // site_packages_dirs() only walks lib/<pyver>/site-packages on unix; on
+        // Windows it looks at Lib/site-packages. Building the posix layout
+        // everywhere left the dist-info invisible to the fingerprint on Windows,
+        // so removing it changed nothing and the assert_ne below could not hold.
+        let site_packages = if cfg!(windows) {
+            venv.join("Lib").join("site-packages")
+        } else {
+            venv.join("lib").join("python3.11").join("site-packages")
+        };
         fs::create_dir_all(site_packages.join("unsloth_cli").join("commands")).unwrap();
         fs::write(
             site_packages