Re. issues with the standard SRFI 64 implementation, let me point out that I've written an alternative implementation with cleaner code and behavior of the default test runner; it's part of this (currently dormant) project:
https://github.com/TaylanUB/scheme-srfis (I've not yet had time to migrate away from GitHub. Sorry.) If I remember correctly, it also runs slightly faster. To use with Guile, just add the root dir of the repo to the load path and import (srfi srfi-64) as usual; it should override the default one if the Guile load path is set up correctly. To make sure you're not overriding other SRFIs offered by Guile, remove all but the following files: srfi/64/* srfi/64.sld srfi/srfi-64.sld Or copy just those into a different directory and add that to your Guile load path. You could also rename 'srfi-64.sld' so as not to override the default SRFI 64, and I think it should still work under the changed name so long as srfi/64/* aren't renamed. -- Taylan