Permission Denied for Accessing Flask Caching

I'm using a flask app starter code, and I'm running into this caching permission issue from vercel dashboard runtime logs when deployed on vercel with vercel ⁠—prod, but don't run into the issue when testing locally with vercel dev.

Is this a caching permission issue with edge functions?

[WARNING]	2023-03-27T04:17:56.207Z	d820d1ac-8e93-4d09-a5a0-7f97292c013e	Exception raised while handling cache file '/var/task/cache/2029240f6d1128be89ddc32729463129'
Traceback (most recent call last):
  File "/var/task/cachelib/file.py", line 209, in get
    with self._safe_stream_open(filename, "rb") as f:
  File "/var/lang/lib/python3.9/contextlib.py", line 119, in __enter__
    return next(self.gen)
  File "/var/task/cachelib/file.py", line 330, in _safe_stream_open
    fs = self._run_safely(open, path, mode)
  File "/var/task/cachelib/file.py", line 324, in _run_safely
    output = fn(*args, **kwargs)
PermissionError: [Errno 13] Permission denied: '/var/task/cache/2029240f6d1128be89ddc32729463129'[WARNING]	2023-03-27T04:17:56.208Z	d820d1ac-8e93-4d09-a5a0-7f97292c013e	Exception raised while handling cache file '/var/task/cache/2029240f6d1128be89ddc32729463129'
Traceback (most recent call last):
  File "/var/task/cachelib/file.py", line 209, in get
    with self._safe_stream_open(filename, "rb") as f:
  File "/var/lang/lib/python3.9/contextlib.py", line 119, in __enter__
    return next(self.gen)
  File "/var/task/cachelib/file.py", line 330, in _safe_stream_open
    fs = self._run_safely(open, path, mode)
  File "/var/task/cachelib/file.py", line 324, in _run_safely
    output = fn(*args, **kwargs)
PermissionError: [Errno 13] Permission denied: '/var/task/cache/2029240f6d1128be89ddc32729463129'[WARNING]	2023-03-27T04:17:56.208Z	d820d1ac-8e93-4d09-a5a0-7f97292c013e	Exception raised while handling cache file '/var/task/cache/85cd70373cda23597cde41f6a0be4bed'
Traceback (most recent call last):
  File "/var/task/cachelib/file.py", line 248, in set
    fd, tmp = tempfile.mkstemp(
  File "/var/lang/lib/python3.9/tempfile.py", line 336, in mkstemp
    return _mkstemp_inner(dir, prefix, suffix, flags, output_type)
  File "/var/lang/lib/python3.9/tempfile.py", line 255, in _mkstemp_inner
    fd = _os.open(file, flags, 0o600)
OSError: [Errno 30] Read-only file system: '/var/task/cache/tmpc8_tjfew.__wz_cache'

Start by reviewing the deployed Vercel runtime logs and the cachelib/file.py paths shown in the traceback, then compare them with the local vercel dev behavior. Confirm whether the Flask cache is attempting writes under /var/task/cache and document the supported configuration or reproduction steps for a writable cache location.