quick fix; ok json response ~~

src/binary_formats.ml

@@ -188,7 +188,9 @@ module UTIL = struct
 
     let hash s =
       match String.length s = 32 with
-      | false -> Fmt.failwith "SHA256 failure: data is not 32 bytes"
+      | false ->
+          Fmt.failwith "SHA256 failure: data is not 32 bytes, instead is %d"
+            (String.length s)
       | true -> hash s
   end
 
@@ -218,7 +220,7 @@ module UTIL = struct
     val bin : t Bin.t
     val hash : M.src -> t
   end = struct
-    include Hash_64
+    include HHH_64
 
     let hash src = hash (M.to_octets src)
   end
@@ -233,7 +235,7 @@ module UTIL = struct
     val bin : t Bin.t
     val hash : M.src -> t
   end = struct
-    include Hash_32
+    include HHH_32
 
     let hash src = hash (M.to_octets src)
   end