Sylvain Henry authored May 23, 2025 and Marge Bot committed Mar 27, 2026

We don't need to create a transaction for the rhs of (catchRetry#)
because contrary to the lhs we don't need to abort it on retry. Moreover
it is particularly harmful if we have code such as (#26028):

  let cN = readTVar vN >> retry
      tree = c1 `orElse` (c2 `orElse` (c3 `orElse` ...))
  atomically tree

Because it will stack transactions for the rhss and the read-sets of all
the transactions will be iteratively merged in O(n^2) after the
execution of the most nested retry.

This is the second attempt at implementing this. The first attempt
triggered segfaults (#26291) and has been reverted.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>