Perhaps a malloc error on CI machines

src/modules/bulletproofs/bulletproofs_pp_norm_product_impl.h

@@ -235,7 +235,7 @@ int secp256k1_bulletproofs_pp_rangeproof_norm_product_prove(
     size_t scratch_checkpoint;
     size_t log_n = secp256k1_bulletproofs_pp_log2(g_len), log_m = secp256k1_bulletproofs_pp_log2(h_len);
     size_t n_rounds = log_n > log_m ? log_n : log_m;
-
+    printf("n_rounds: %d\n");
     /* Check proof sizes.*/
     if (*proof_len < 65 * n_rounds + 64) {
         return 0;
@@ -257,8 +257,10 @@ int secp256k1_bulletproofs_pp_rangeproof_norm_product_prove(
     gs = (secp256k1_ge*)secp256k1_scratch_alloc(&ctx->error_callback, scratch, (g_len + h_len) * sizeof(secp256k1_ge));
     if (ns == NULL || ls == NULL || cs == NULL || gs == NULL) {
         secp256k1_scratch_apply_checkpoint(&ctx->error_callback, scratch, scratch_checkpoint);
+        printf("Failed to allocate memory for proof.\n");
         return 0;
     }
+    printf("Here\n");
     memcpy(ns, n_vec, g_len * sizeof(secp256k1_scalar));
     memcpy(ls, l_vec, h_len * sizeof(secp256k1_scalar));
     memcpy(cs, c_vec, h_len * sizeof(secp256k1_scalar));