I've just published draft #2 of SRFI 155.  It was submitted
by Marc Nieper-Wißkirchen, author of the SRFI.

  <https://srfi.schemers.org/srfi-155/>

Here are Marc's comments on the draft:

  - Minor spelling/grammar fixes.

  - Added optional procedure ‘forcing-environment’ that
  allows to implement the original R7RS semantics on top of
  SRFI 155.

  - Added (orthogonal) requirement that implementations have
  to rewrite (delay (force ...)).

Here's the diff:

  <https://github.com/scheme-requests-for-implementation/srfi-155/compare/8febaba92e747d7e9f2492db4adff874658b9ed6...ee62ed19ba7123173088634a773e6cafab31c11d>

Regards,

SRFI Editor