diff -u guile-nettle-0.3.0.8-c2e5/libguile-nettle.c patched/libguile-nettle.c
--- guile-nettle-0.3.0.8-c2e5/libguile-nettle.c	2020-09-22 07:38:24.000000000 +0200
+++ patched/libguile-nettle.c	2020-09-22 08:06:59.044627220 +0200
@@ -30,16 +30,10 @@
 static void
 guile_nettle_random_func (void *ctx, size_t length, uint8_t * dst)
 {
-  SCM *cb = ctx;
-  SCM scm_length = scm_from_size_t (length);
-  SCM random_data = scm_call_1 (*cb, scm_length);
-  size_t output_length = scm_c_bytevector_length (random_data);
   size_t i;
-  SCM_ASSERT (output_length == length,
-              *cb, SCM_ARGn, "generating random data");
   for (i = 0; i < length; i++)
     {
-      dst[i] = scm_c_bytevector_ref (random_data, i);
+      dst[i] = rand () % 256;
     }
 }