@item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
@item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
@item
-@c FIXME: Specify a version number once a release has been made.
+@c FIXME: We need the #:fetch-options parameter of 'submodule-update',
+@c which appeared in 0.5.0. Change below after string freeze.
@uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
or later;
@item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
guix import json hello.json
@end example
-@item nix
-Import metadata from a local copy of the source of the
-@uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
-relies on the @command{nix-instantiate} command of
-@uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
-typically written in a mixture of Nix-language and Bash code. This
-command only imports the high-level package structure that is written in
-the Nix language. It normally includes all the basic fields of a
-package definition.
-
-When importing a GNU package, the synopsis and descriptions are replaced
-by their canonical upstream variant.
-
-Usually, you will first need to do:
-
-@example
-export NIX_REMOTE=daemon
-@end example
-
-@noindent
-so that @command{nix-instantiate} does not try to open the Nix database.
-
-As an example, the command below imports the package definition of
-LibreOffice (more precisely, it imports the definition of the package
-bound to the @code{libreoffice} top-level attribute):
-
-@example
-guix import nix ~/path/to/nixpkgs libreoffice
-@end example
-
@item hackage
@cindex hackage
Import metadata from the Haskell community's central package archive
@item @code{ident-file} (default: @code{%default-postgres-ident})
Filename or G-expression for the user name mapping configuration.
-@item @code{socket-directory} (default: @code{"/var/run/postgresql"})
+@item @code{socket-directory} (default: @code{#false})
Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
-is to listen for connections from client applications. If set to
-@code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
+is to listen for connections from client applications. If set to
+@code{""} PostgreSQL does not listen on any Unix-domain sockets, in
which case only TCP/IP sockets can be used to connect to the server.
+By default, the @code{#false} value means the PostgreSQL default value
+will be used, which is currently @samp{/tmp}.
+
@item @code{extra-config} (default: @code{'()})
List of additional keys and values to include in the PostgreSQL config
file. Each entry in the list should be a list where the first element