check_python_dependencies: If overriding requirements.txt path, provide a pip command line

Advice about install.sh/install.bat, etc only works for the default requirements.txt

tools/check_python_dependencies.py

@@ -39,10 +39,12 @@ def escape_backslash(path):
 if __name__ == "__main__":
     idf_path = os.getenv("IDF_PATH")
 
+    default_requirements_path = os.path.join(idf_path, 'requirements.txt')
+
     parser = argparse.ArgumentParser(description='ESP32 Python package dependency checker')
     parser.add_argument('--requirements', '-r',
                         help='Path to the requrements file',
-                        default=os.path.join(idf_path, 'requirements.txt'))
+                        default=default_requirements_path)
     args = parser.parse_args()
 
     not_satisfied = []
@@ -64,7 +66,10 @@ if __name__ == "__main__":
         print('The following Python requirements are not satisfied:')
         for requirement in not_satisfied:
             print(requirement)
-        if os.environ.get('IDF_PYTHON_ENV_PATH'):
+        if os.path.realpath(args.requirements) != os.path.realpath(default_requirements_path):
+            # we're using this script to check non-default requirements.txt, so tell the user to run pip
+            print('Please check the documentation for the feature you are using, or run "%s -m pip install -r %s"' % (sys.executable, args.requirements))
+        elif os.environ.get('IDF_PYTHON_ENV_PATH'):
             # We are running inside a private virtual environment under IDF_TOOLS_PATH,
             # ask the user to run install.bat again.
             if sys.platform == "win32" and not os.environ.get("MSYSTEM"):