I thought I'd post a brief summary of my tests of the SRFI 152 sample
implementation.

Short version: Worked fine with Chicken and Chibi, but needed a few
small changes for Kawa.

Longer version:

All tests are on a 32-bit x86 Debian 8 (Jessie) system.

  - Tested Chicken implementation (with Chicken Version 4.9.0.1)
    using both of the following, and all tests pass.
    - `csi srfi-152.scm chicken-test.scm'
    - `csi utf8-srfi-152.scm utf8-chicken-test.scm'

  - Tested portable implementation with Chibi (version 0.7.3) using
    `chibi-scheme chibi-test.scm' and all tests pass.

  - Tested portable implementation with Kawa (version 2.93):
    - Kawa complained about duplicate definitions in `portable.scm' and so
      commented out the definitions of `string-map', `%string-map', and
      `string->vector'.
    - Made a few small changes to `chibi-test.scm' to yield
      `my-kawa-test.scm' that works with Kawa:
      - replaced `(chibi test)' with `(srfi 64)'
      - added a syntax-definition for `test', defined as `test-equal'.
      - added a `begin-test' form before all the tests.
      - replaced the `(test-exit)' at the end with a `(test-end)'.
    - With above changes, all tests pass.

Regards,

-chaw