Fix env var bug

Author: niechen

src/mcpm/clients/base.py

@@ -164,7 +164,7 @@ def to_client_format(self, server_config: ServerConfig) -> Dict[str, Any]:
         }
 
         # Add filtered environment variables if present
-        non_empty_env = server_config.get_filtered_env_vars()
+        non_empty_env = server_config.get_filtered_env_vars(os.environ)
         if non_empty_env:
             result["env"] = non_empty_env
 

src/mcpm/utils/server_config.py

@@ -67,18 +67,25 @@ def to_dict(self) -> Dict:
         # We keep it for backwards compatibility
         return self.model_dump(exclude_none=True)
 
-    def get_filtered_env_vars(self) -> Dict[str, str]:
+    def get_filtered_env_vars(self, env: Dict[str, str]) -> Dict[str, str]:
         """Get filtered environment variables with empty values removed
         
         This is a utility for clients to filter out empty environment 
         variables, regardless of client-specific formatting.
         
+        Args:
+            env: Dictionary of environment variables to use for resolving
+                 ${VAR_NAME} references.
+        
         Returns:
             Dictionary of non-empty environment variables
         """
         if not self.env_vars:
             return {}
 
+        # Use provided environment without falling back to os.environ
+        environment = env
+            
         # Filter out empty environment variables
         non_empty_env = {}
         for key, value in self.env_vars.items():
@@ -88,7 +95,7 @@ def get_filtered_env_vars(self) -> Dict[str, str]:
                 if value.startswith("${") and value.endswith("}"):
                     # Extract the variable name from ${VAR_NAME}
                     env_var_name = value[2:-1]
-                    env_value = os.environ.get(env_var_name, "")
+                    env_value = environment.get(env_var_name, "")
                     # Only include if the variable has a value in the environment
                     if env_value.strip() != "":
                         non_empty_env[key] = value