From c14e10503ed853e0eb2be20698c3cb8559c2c591 Mon Sep 17 00:00:00 2001
From: Alexey Khudyakov <alexey.skladnoy@gmail.com>
Date: Sun, 16 Feb 2025 23:50:01 +0300
Subject: [PATCH] Capture InterruptMain during takeMVar

Otherwise if exception wasn't captured during execution it will surface when we
lock on MVar
---
 ChangeLog.md                | 4 ++++
 src/Python/Internal/Eval.hs | 4 +++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 429037b..ed87066 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+NEXT VERSION []
+------------------
+* Crash of python's main thread when one attempts to interrupt it fixed.
+
 0.1.1 [2025.02.13]
 ------------------
 * Number of deadlocks in `runPyInMain` fixed:
diff --git a/src/Python/Internal/Eval.hs b/src/Python/Internal/Eval.hs
index faf1f67..ca5970d 100644
--- a/src/Python/Internal/Eval.hs
+++ b/src/Python/Internal/Eval.hs
@@ -362,7 +362,7 @@ mainThread lock_init lock_eval = do
   case r_init of
     False -> pure ()
     True  -> mask_ $ fix $ \loop ->
-      takeMVar lock_eval >>= \case
+      (takeMVar lock_eval `catch` (\InterruptMain -> pure HereWeGoAgain)) >>= \case
         EvalReq py resp -> do
           res <- (Right <$> runPy py) `catch` (pure . Left)
           putMVar resp res
@@ -373,6 +373,7 @@ mainThread lock_init lock_eval = do
             Py_Finalize();
             } |]
           putMVar resp ()
+        HereWeGoAgain -> loop
 
 
 doInializePythonIO :: IO Bool
@@ -431,6 +432,7 @@ doInializePythonIO = do
 data EvalReq
   = forall a. EvalReq (Py a) (MVar (Either SomeException a))
   | StopReq (MVar ())
+  | HereWeGoAgain
 
 data InterruptMain = InterruptMain
   deriving stock    Show