Considering deprecating the checkpoint mechanism #626

We may need to deprecate the checkpoint mechanism, as we are not currently aware of anyone using it actively. Introduced in FORM version 4.0, the checkpoint mechanism allows users to save intermediate computation states, enabling recovery after crashes. However, maintaining this functionality has always required significant effort. The current implementation is likely to contain bugs, as it has not been thoroughly tested, partly due to our limited human resources.

Users using the checkpoint mechanism will see a deprecation warning. To suppress the warning, use the -ignore-deprecation command line option or set the environment variable FORM_IGNORE_DEPRECATION=1.

This does not mean that support will be dropped immediately. However, support for the checkpoint mechanism, including its own bug fixes and compatibility with new features, may be delayed or not provided at all. If we receive no feedback from users, the checkpoint mechanism will be removed from the codebase at some point. If you want this support to continue, please leave a comment on this issue.