Mortimer,

> So I wrote a packaging recipe (below) and submitted to nonfree. 
> Was told
> it might be that no one has gotten around to packaging for main 
> yet.

Just FYI, Guix doesn't have sections like Debian.  There is only a 
single guix git repository, containing all packages supported and 
maintained by the Guix project.

Guix deals exclusively in Free software.  Any third-party 
repositories that don't follow the GNU Free Software Distribution 
Guidelines are not affiliated with GNU or Guix, and we can't 
provide support for them here.

I'm not aware of any licence issues with PostgreSQL, however, so 
we cool.

> I see
> the documentation for submitting patches, but not recipe 
> files. Is there a
> protocol for submitting packaging recipes?

There's no difference! :-)  Guix packages (=‘recipes’) are added 
to the repository as patches.  That's it.  Same as any other 
addition or fix: packages are just code, after all.

To submit a package upstream to Guix, you'd check out the git 
repository, add your package (‘recipe’) to a file that best suits 
it (here: databases.scm), commit it and send a patch as described 
in that section of the manual.

However…

>   (description "This package contains client and administrative 
>   programs
> for PostgreSQL: these are the interactive terminal client psql 
> and programs
> for creating and removing users and databases.")

…I'm a bit confused.  What exactly is missing?

λ ls $(guix build postgresql)/*bin
clusterdb          pg_config       pg_test_fsync
createdb           pg_controldata  pg_test_timing
createuser         pg_ctl          pg_upgrade
dropdb             pg_dump         pg_verifybackup
dropuser           pg_dumpall      pg_waldump
ecpg               pg_isready      postgres
initdb             pg_receivewal   postmaster
oid2name           pg_recvlogical  psql
pg_archivecleanup  pg_resetwal     reindexdb
pg_basebackup      pg_restore      vacuumdb
pgbench            pg_rewind       vacuumlo
pg_checksums       pg_standby

Sorry to be so dense.  I do use PostgreSQL but only know the very 
basics, I haven't even used or heard of most of those commands.

Kind regards,

T G-R