diff --git a/src/plugins/metrics/metrics_cilast.ml b/src/plugins/metrics/metrics_cilast.ml
index 6cef7e541ab3fe1d2e2f7b6e0c97343e2bd64307..eee8a7cb2c7ddb645508dbc005c53d62271f402e 100644
--- a/src/plugins/metrics/metrics_cilast.ml
+++ b/src/plugins/metrics/metrics_cilast.ml
@@ -747,9 +747,9 @@ let compute_on_cilast ~libc =
          Format.fprintf fmt "@." (* ensure the file ends with a newline *)
       );
       close_out oc;
-    with Sys_error _ ->
-      Metrics_parameters.failure "Cannot open file %a.@."
-        Filepath.Normalized.pretty out_fname
+    with Sys_error s ->
+      Metrics_parameters.abort "Cannot open file %a (%s)."
+        Filepath.Normalized.pretty out_fname s
   end
   else Metrics_parameters.result "%a" pp_with_funinfo cil_visitor