Weird warnings from loopy

[andrewlhicks]

Hello all,

I recently installed firedrake on a fresh install of Ubuntu 24.04 on WSL. After successfully completing the install, importing firedrake gives some warnings:

>>> import firedrake
/home/andrewh/firedrake/src/loopy/loopy/schedule/__init__.py:2201: UserWarning: pytools.persistent_dict 'loopy-schedule-cache-v4-2024.1-islpy2024.1-cgen2020.1-967461ba9c3677ee6f0334b9ee95ef0f0e51d208-v1': enabling safe_sync as default. This provides strong protection against data loss, but can be unnecessarily expensive for use cases such as caches.Pass 'safe_sync=False' if occasional data loss is tolerable. Pass 'safe_sync=True' to suppress this warning.
  schedule_cache = WriteOncePersistentDict(
/home/andrewh/firedrake/src/loopy/loopy/tools.py:914: UserWarning: pytools.persistent_dict 'loopy-memoize-cache-buffer_array-LoopyKeyBuilder.LoopyKeyBuilder-v0-2024.1-islpy2024.1-cgen2020.1-967461ba9c3677ee6f0334b9ee95ef0f0e51d208-v1': enabling safe_sync as default. This provides strong protection against data loss, but can be unnecessarily expensive for use cases such as caches.Pass 'safe_sync=False' if occasional data loss is tolerable. Pass 'safe_sync=True' to suppress this warning.
  transform_cache = WriteOncePersistentDict(
/home/andrewh/firedrake/src/loopy/loopy/tools.py:914: UserWarning: pytools.persistent_dict 'loopy-memoize-cache-preprocess_program-LoopyKeyBuilder.LoopyKeyBuilder-v0-2024.1-islpy2024.1-cgen2020.1-967461ba9c3677ee6f0334b9ee95ef0f0e51d208-v1': enabling safe_sync as default. This provides strong protection against data loss, but can be unnecessarily expensive for use cases such as caches.Pass 'safe_sync=False' if occasional data loss is tolerable. Pass 'safe_sync=True' to suppress this warning.
  transform_cache = WriteOncePersistentDict(
/home/andrewh/firedrake/src/loopy/loopy/codegen/__init__.py:313: UserWarning: pytools.persistent_dict 'loopy-code-gen-cache-v3-2024.1-islpy2024.1-cgen2020.1-967461ba9c3677ee6f0334b9ee95ef0f0e51d208-v1': enabling safe_sync as default. This provides strong protection against data loss, but can be unnecessarily expensive for use cases such as caches.Pass 'safe_sync=False' if occasional data loss is tolerable. Pass 'safe_sync=True' to suppress this warning.
  code_gen_cache = WriteOncePersistentDict(
/home/andrewh/firedrake/src/loopy/loopy/target/execution.py:724: UserWarning: pytools.persistent_dict 'loopy-typed-and-scheduled-cache-v1-2024.1-islpy2024.1-cgen2020.1-967461ba9c3677ee6f0334b9ee95ef0f0e51d208-v1': enabling safe_sync as default. This provides strong protection against data loss, but can be unnecessarily expensive for use cases such as caches.Pass 'safe_sync=False' if occasional data loss is tolerable. Pass 'safe_sync=True' to suppress this warning.
  typed_and_scheduled_cache = WriteOncePersistentDict(
/home/andrewh/firedrake/src/loopy/loopy/target/execution.py:732: UserWarning: pytools.persistent_dict 'loopy-invoker-cache-v10-2024.1-islpy2024.1-cgen2020.1-967461ba9c3677ee6f0334b9ee95ef0f0e51d208-v1': enabling safe_sync as default. This provides strong protection against data loss, but can be unnecessarily expensive for use cases such as caches.Pass 'safe_sync=False' if occasional data loss is tolerable. Pass 'safe_sync=True' to suppress this warning.
  invoker_cache = WriteOncePersistentDict(

Any idea as to why this is happening? I would just pass safe_sync=True like the warning states, but I don't know how to do that in this case.

[connorjward]

This is due to a recent update to pytools (a Firedrake dependency). This warning will likely go away when we upgrade our fork of loopy (done every few months, though this suggests we should really do it soon).

In the meantime you can try hiding the warnings by passing -W<something> when you call python (docs). This isn't recommended generally but if the warnings are problematic then this is the simplest short term way to hide them.

[andrewlhicks]

Just did a fresh install of Firedrake, and the warning is gone.