gnu: Add rpc-daemon service

* gnu/services/nfs.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

gnu: Add 'package-for-guile-2.2' procedure and use it.

* gnu/packages/guile.scm (guile-2.2-package-name)
(package-for-guile-2.2): New procedures.
* gnu/packages/guile.scm (guile2.2-json, guile2.2-minikanren)
(guile2.2-irregex, guile2.2-commonmark): New variables.

gnu: guile-commonmark: Remove hard-coded "/2.0" in installation directories.

* gnu/packages/guile.scm (guile-commonmark)[source]: Add 'snippet' and
'modules'.

gnu: guile-json: Remove hard-coded Guile effective version.

* gnu/packages/guile.scm (guile-json)[snippet]: Modify 'ac_subst_vars'
in 'configure', and use "@GUILE_EFFECTIVE_VERSION@" instead of "2.0" in
'Makefile.in'.

gnu: guile-minikanren: Remove hard-coded Guile effective version.

* gnu/packages/guile.scm (guile-minikanren)[arguments]: Remove (ice-9
match) from #:modules.  Use 'open-pipe*' to determine the effective
version of Guile, and use that to compute MODULE-DIR.

gnu: guile-irregex: Remove hard-coded Guile effective version.

* gnu/packages/guile.scm (guile-irregex)[arguments]: Add (ice-9 popen)
and (ice-9 rdelim).  Remove nested 'use-modules' form.  Call
'open-pipe*' to determine Guile's effective version, and use it to
compute MODULE-DIR.

gnu: Enable tcp-wrappers for nrircd.

* gnu/packages/messaging.scm (ngircd) [inputs]: Add tcp-wrappers.

gnu: Add tcp-wrappers.

* gnu/packages/networking.scm (tcp-wrappers): New variable.

bash completion: Complete subcommands and their options.

* etc/completion/bash/guix (_guix_complete_subcommand): New function.
(_guix_complete_option): Allow completion of subcommand options.
(_guix_complete): Use '_guix_complete_subcommand' for "system" and
"import".

bash completion: Redirect 'guix' stderr to /dev/null.

This avoids spurious messages when pressing TAB.

* etc/completion/bash/guix (_guix_complete_available_package)
(_guix_complete_installed_package, _guix_complete_option)
(_guix_complete): Redirect stderr to /dev/null when running 'guix'.

Add Zsh completion file.

* etc/completion/zsh/_guix: New file.
* Makefile.am (dist_zshcompletion_DATA): New variable.
* configure.ac: Add --with-zsh-completion-dir.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add mpop.

* gnu/packages/mail.scm (mpop): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

guix hash: Add --exclude-vcs option.

* guix/scripts/hash.scm (show-help): Add help text for --exclude-vcs option.
(%options): Add --exclude-vcs option.
(guix-hash): Handle exclude-vcs option.
* doc/guix.texi ("Invoking guix hash"): Update doc.
* tests/guix-hash.sh: Add test.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

services: syslog: Use a PID file.

* gnu/services/base.scm (syslog-service-type)[start]: Remove --no-detach
and use #:pid-file.

gnu: inetutils: Use /var as the localstatedir.

* gnu/packages/admin.scm (inetutils)[arguments]: Add #:configure-flags.

gnu: rottlog: Adjust the default 'weekly' config.

* gnu/packages/admin.scm (rottlog)[arguments]: Add 'tweak-rc-weekly'
phase.

gnu: rottlog: Read configuration files from /etc/rottlog.

* gnu/packages/admin.scm (rottlog)[arguments]: Set
ROTT_ETCDIR=/etc/rottlog in #:configure-flags and add #:make-flags.

gnu: rottlog: Set default value for 'packdir'.

* gnu/packages/admin.scm (rottlog)[arguments]: Add 'set-packdir' phase.

gnu: rottlog: Use 'modify-phases'.

* gnu/packages/admin.scm (rottlog)[arguments]: Use 'modify-phases'.

gnu: Add perl-curses.

* gnu/packages/ncurses.scm (perl-curses): New variable.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>