The program no longer contains any instances of pthread_cancel(),
and pthread_testcancel() does not do anything if pthread_cancel()
was never used

--- a/src/CImg.h
+++ b/src/CImg.h
@@ -10164,7 +10164,6 @@ namespace cimg_library {
           X11_attr.unlock();
           cimg::sleep(8);
         }
-        pthread_testcancel();
       }
       return 0;
     }