fix: make .env file optional on regtest (#657)

build.py

@@ -1,22 +1,37 @@
 #! /bin/python3
 
 import sys
+import json
+
+def handle_coop_disabled():
+    print("Cooperative signatures are disabled in config")
+    sys.exit(1)
 
 with open("./src/config.ts", "r") as f:
     for line in f:
         if "cooperativeDisabled" not in line:
             continue
 
-        if "true" in line:
-            print("Cooperative signatures are disabled in config")
-            sys.exit(1)
+        if "false" not in line:
+            handle_coop_disabled()
+
+network: str | None = None
+
+with open("./public/config.json") as f:
+    data = json.load(f)
+
+    network = data["network"]
+
+    if data.get("cooperativeDisabled", False):
+        handle_coop_disabled()
 
-        break
 
-with open(".env", "r") as f:
-    data = f.read()
+# .env file is not required on regtest
+if network != "regtest":
+    with open(".env", "r") as f:
+        data = f.read()
 
-    for var in ["VITE_RSK_LOG_SCAN_ENDPOINT"]:
-        if var not in data:
-            print(f"{var} not in .env file")
-            sys.exit(1)
+        for var in ["VITE_RSK_LOG_SCAN_ENDPOINT"]:
+            if var not in data:
+                print(f"{var} not in .env file")
+                sys.exit(1)