I'm not sure i this is for the guix-help ml or for the guile-users ml

I'll move this to the appropriate place, if you will indicate it to me.
Thanks.

On my GuixSD system, I'm trying to get my feet wet with cwebber's squee
https://notabug.org/cwebber/guile-squee

I have this line
(define conn (connect-to-postgres-paramstring "dbname=tryton
user=postgres"))

then, in the REPL, I try

scheme@(squee)> conn

and I get

$4 = ././././squee.scm:131:29: In procedure #<procedure 1998560 at
././././squee.scm:129:2 (pg-conn port)>:
././././squee.scm:131:29: In procedure unwrap-pg-conn: Wrong type argument:
Error while printing exception.

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.

Of course I get this same exception also if I try to run a query, with the
same connection

Previously, I changed this line
(define libpq (dynamic-link "libpq"))

to
(define libpq (dynamic-link
"/gnu/store/0fqfm833m1g3603l0vifbzg6kqaqad24-postgresql-9.5.6/lib/libpq.so"))

that's the postgres that's installed in my profile

But there are 3 more postgreses in my store

~$ ls /gnu/store/ | grep postgresql
[...]
0fqfm833m1g3603l0vifbzg6kqaqad24-postgresql-9.5.6/
[...]
5x35az6lbi7y0zd4z45b7kv1qp67aqac-postgresql-9.5.6/
[...]
dwbscplq276xzcfzryda7g5097p23974-postgresql-9.5.6/
[...]
hmdqm7xvshlf6ljwck77nap821jzg677-postgresql-9.5.6/

I don't know why. I have configured my system with a postgresql service
running. Maybe the service is using a different package form the one
installed in my profile ?

I don't know

And what about the other 2 postgreses ?

Anyway, about my my screech with squee: Is it because I'm linking
incorrectly to the postgres library ?

Or is this because the code is not fresh (last edit was "one year ago") ?

Thanks in advance