Fix build

scripts/build-frontend.py

@@ -1,4 +1,5 @@
 # noqa: INP001
+import os
 import shutil
 import subprocess
 
@@ -17,6 +18,10 @@ class CustomBuildHook(BuildHookInterface):
             raise RuntimeError(
                 "NodeJS `npm` is required for building Cista but it was not found"
             )
-        frontend = "frontend"
-        subprocess.run([npm, "install", "--prefix", frontend], check=True)  # noqa: S603
-        subprocess.run([npm, "run", "build", "--prefix", frontend], check=True)  # noqa: S603
+        # npm --prefix doesn't work on Windows, so we chdir instead
+        os.chdir("frontend")
+        try:
+            subprocess.run([npm, "install"], check=True)  # noqa: S603
+            subprocess.run([npm, "run", "build"], check=True)  # noqa: S603
+        finally:
+            os.chdir("..")