add "[FATAL]" marker on abort

Indicate that the situation is fatal.

1 files changed, 1 insertions, 0 deletions

diff --git a/error.c b/error.c
index 3a63a5f2a9..408a163f1f 100644
--- a/error.c
+++ b/error.c
@@ -2640,6 +2640,7 @@ rb_raise(VALUE exc, const char *fmt, ...)
     }
     else {
         /* Not in a ruby thread */
+        fprintf(stderr, "%s", "[FATAL] ");
         vfprintf(stderr, fmt, args);
         abort();
     }