Exception annotations were introduced in GHC 9.10, and can be an invaluable tool for debugging thorny problems. The initial implementation had some important limitations that made them less useful in practice than one might hope, but fortunately the situation has since been much improved. In this blog post we will give a detailed overview of the status quo as of GHC 9.12/9.14, identify some gotchas you should be aware and provide advise on how to deal with them, and briefly look ahead to what will change in GHC 10.0. We will also dedicate a section to discussing the problems in GHC 9.10, for those who cannot yet upgrade.

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