Just checking with the author.  John, what do you think?

---------- Forwarded message ----------
From: "Shiro Kawai" <xxxxxx@gmail.com>
Date: Apr 23, 2016 6:51 PM
Subject: Reference implementation of set-comparator/bag-comparator
To: <srfi-113@srfi.schemers.org>
Cc:

The result of sob-hash function in the original reference implementation depends
on the order that hash-table-for-each visits entries, but I believe it should not.
The PR is a suggested fix--there may be a better one.

https://github.com/scheme-requests-for-implementation/srfi-113/pull/1

The change in sets-test.scm is the one exhibits the bug on Gauche, but whether
it reveals the bug or not depends on the implementation of hash tables.

I tested it with the change applied to Gauche source, but haven't tested
the PR itself.