PaymentServer/Ristretto.hs uses Control.Exception.bracket which uses interruptable masking

[exarkun]

From https://www.snoyman.com/blog/2020/10/haskell-bad-parts-1:

And Control.Exception.bracket uses interruptible masking for it’s cleanup handler. So if you need to perform some kind of blocking action in your cleanup, and you want to make sure that you don’t get interrupted by an async exception, you have to remember to use uninterruptibleMask yourself. Otherwise, your cleanup action may not complete, which is Bad News Bears.

The Ristretto code uses bracket to ensure memory gets freed. Only if it gets interrupted by an async exception, then maybe the memory won't be free after all.