--- src/gufoEngine.ml.orig	2020-03-29 00:19:15.000000000 +0800
+++ src/gufoEngine.ml	2025-10-18 13:38:44.000000000 +0800
@@ -26,6 +26,10 @@
 open Array
 open Printf
 
+(* Retry waitpid on EINTR. Some libraries (terminal, signals) can interrupt waitpid. *)
+let rec waitpid_no_intr flags pid =
+  try Unix.waitpid flags pid
+  with Unix.Unix_error (Unix.EINTR, "waitpid", _) -> waitpid_no_intr flags pid
 
 let print_debug_arg2valMap arg2valMap = 
   debug_print "DUMPING arg2ValMap";
@@ -940,7 +944,7 @@
   in 
   match to_fork with
     | true -> (0, MOSimpleCmd cmd)
-    | false -> let (_, processstatus) =  Unix.waitpid [] pid in
+    | false -> let (_, processstatus) =  waitpid_no_intr [] pid in
                let res = match processstatus with
                          | Unix.WEXITED i -> i
                          | Unix.WSIGNALED i -> i
@@ -1036,7 +1040,7 @@
     match to_fork with
       | true -> (0, MOSimpleCmd cmd)
       | false -> 
-                let (_, processstatus) =  Unix.waitpid [] pid in
+                let (_, processstatus) =  waitpid_no_intr [] pid in
                 let res = match processstatus with
                           | Unix.WEXITED i -> i
                           | Unix.WSIGNALED i -> i
@@ -1095,7 +1099,7 @@
                    with _ -> () 
                 done;
                   Stream.iter (fun achar -> output_char stdout_channel_out achar) stdout_stream; 
-                let (_, processstatus) =  Unix.waitpid [] pid in
+                let (_, processstatus) =  waitpid_no_intr [] pid in
                 let res = match processstatus with
                           | Unix.WEXITED i -> i
                           | Unix.WSIGNALED i -> i