better missing system package message (#4306)

* better missing system package message

* change error type

reflex/constants/__init__.py

@@ -2,6 +2,8 @@
 
 from .base import (
     COOKIES,
+    IS_LINUX,
+    IS_MACOS,
     IS_WINDOWS,
     LOCAL_STORAGE,
     POLLING_MAX_HTTP_BUFFER_SIZE,

reflex/constants/base.py

@@ -13,6 +13,8 @@ from platformdirs import PlatformDirs
 from .utils import classproperty
 
 IS_WINDOWS = platform.system() == "Windows"
+IS_MACOS = platform.system() == "Darwin"
+IS_LINUX = platform.system() == "Linux"
 
 
 class Dirs(SimpleNamespace):

reflex/utils/exceptions.py

@@ -1,5 +1,7 @@
 """Custom Exceptions."""
 
+from typing import NoReturn
+
 
 class ReflexError(Exception):
     """Base exception for all Reflex exceptions."""
@@ -147,3 +149,25 @@ class DynamicComponentInvalidSignature(ReflexError, TypeError):
 
 class InvalidPropValueError(ReflexError):
     """Raised when a prop value is invalid."""
+
+
+class SystemPackageMissingError(ReflexError):
+    """Raised when a system package is missing."""
+
+
+def raise_system_package_missing_error(package: str) -> NoReturn:
+    """Raise a SystemPackageMissingError.
+
+    Args:
+        package: The name of the missing system package.
+
+    Raises:
+        SystemPackageMissingError: The raised exception.
+    """
+    from reflex.constants import IS_MACOS
+
+    raise SystemPackageMissingError(
+        f"System package '{package}' is missing."
+        " Please install it through your system package manager."
+        + (f" You can do so by running 'brew install {package}'." if IS_MACOS else "")
+    )

reflex/utils/prerequisites.py

@@ -35,7 +35,10 @@ from reflex import constants, model
 from reflex.compiler import templates
 from reflex.config import Config, environment, get_config
 from reflex.utils import console, net, path_ops, processes
-from reflex.utils.exceptions import GeneratedCodeHasNoFunctionDefs
+from reflex.utils.exceptions import (
+    GeneratedCodeHasNoFunctionDefs,
+    raise_system_package_missing_error,
+)
 from reflex.utils.format import format_library_name
 from reflex.utils.registry import _get_npm_registry
 
@@ -820,11 +823,7 @@ def install_node():
 
 
 def install_bun():
-    """Install bun onto the user's system.
-
-    Raises:
-        FileNotFoundError: If required packages are not found.
-    """
+    """Install bun onto the user's system."""
     win_supported = is_windows_bun_supported()
     one_drive_in_path = windows_check_onedrive_in_path()
     if constants.IS_WINDOWS and not win_supported or one_drive_in_path:
@@ -863,7 +862,7 @@ def install_bun():
     else:
         unzip_path = path_ops.which("unzip")
         if unzip_path is None:
-            raise FileNotFoundError("Reflex requires unzip to be installed.")
+            raise_system_package_missing_error("unzip")
 
         # Run the bun install script.
         download_and_run(

tests/units/utils/test_utils.py

@@ -19,7 +19,7 @@ from reflex.utils import (
     types,
 )
 from reflex.utils import exec as utils_exec
-from reflex.utils.exceptions import ReflexError
+from reflex.utils.exceptions import ReflexError, SystemPackageMissingError
 from reflex.vars.base import Var
 
 
@@ -503,7 +503,7 @@ def test_bun_install_without_unzip(mocker):
     mocker.patch("pathlib.Path.exists", return_value=False)
     mocker.patch("reflex.utils.prerequisites.constants.IS_WINDOWS", False)
 
-    with pytest.raises(FileNotFoundError):
+    with pytest.raises(SystemPackageMissingError):
         prerequisites.install_bun()