Catch IOError when a query times out and retry correctly

kore/src/Kore/Rewrite/SMT/Evaluator.hs

@@ -92,6 +92,8 @@ import SMT (
  )
 import SMT qualified
 import SMT.SimpleSMT qualified as SimpleSMT
+import Control.Monad.Catch qualified as Exception
+import Control.Exception (IOException)
 
 {- | Attempt to evaluate the 'Predicate' argument with an optional side
  condition using an external SMT solver.
@@ -186,7 +188,7 @@ decidePredicate onUnknown sideCondition predicates =
             & runMaybeT
   where
     query :: MaybeT Simplifier Result
-    query = SMT.withSolver . evalTranslator $ do
+    query = onErrorUnknown $ SMT.withSolver . evalTranslator $ do
         tools <- Simplifier.askMetadataTools
         Morph.hoist SMT.liftSMT $ do
             predicates' <-
@@ -196,6 +198,9 @@ decidePredicate onUnknown sideCondition predicates =
             traverse_ SMT.assert predicates'
             SMT.check >>= maybe empty return
 
+    onErrorUnknown action =
+        action `Exception.catch` \(_ :: IOException) -> pure Unknown
+
     retry = retryWithScaledTimeout $ query <* debugRetrySolverQuery predicates
 
 retryWithScaledTimeout :: MonadSMT m => m Result -> m Result