user-login-name, which as Lassi notes, "is reliably accomplished via (user-info:name (user-info (user-uid)))", that the passwd database is the source of truth, but the routines that query it can be overridden with e.g. a LD_PRELOAD hack.  John agreed user-login-name should go, I will add a note pointing out Lassi's alternative.

I originally advocated against all of 3.6 User and group database access, user-info and group-info, but there are solid arguments for them including the above observation by Lassi.

I note group-info:members is particularly messy to get back from the library call, and Lassi notes "getgroups() [ which the SRFI supplies as (user-supplementary-gids) ] gets the full list of your own supplementary groups."

Therefore I advocate we remove group-info:members from the group-info record, and make a note about user-supplementary-gids in the 3.6 section.

I further advocate along with Lassi that pw_gecos from the passwd struct be added to the SRFI in the user-info record.  We could call it either full-name or full-name-field, the latter suggestion because other stuff has been added to it in times past.

We should consider if pw_shell in this struct satisfies the 80/20 rule, or omitting it violates people's expectations.  Fields in a record from a struct are normally particularly cheap in pretty much every way.

current-timezone, which can be picked up from the TZ environment variable, and in general deserves being part of its own SRFI.

- Harold