yields "i == -16382" when the assertion fails
--- coreutils-6.9.92/gnulib-tests/test-frexpl.c
+++ coreutils-6.9.92/gnulib-tests/test-frexpl.c
@@ -134,6 +134,9 @@
     {
       int exp = -9999;
       long double mantissa = frexpl (x, &exp);
+      if (exp != i) {
+          printf("i == %d\n",i);
+      }
       ASSERT (exp == i);
       ASSERT (mantissa == 0.5L);
     }