bug#34833: Package search warning about newt

[mikadoZero <mikadozero@yandex.com>]

guix describe:

guix 1bc24bb
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 1bc24bbf00e21a26d9eb71e5c89d941812dcdad7

I have just started getting warning about newt when I search for
packages.  For example `guix package -s iproute` outputs this:

guix package: warning: failed to load '(gnu build svg)':
no code for module (rsvg)
guix package: warning: failed to load '(gnu installer final)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt ethernet)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt final)':
no code for module (parted)
guix package: warning: failed to load '(gnu installer newt keymap)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt locale)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt menu)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt network)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt partition)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt services)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt timezone)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt user)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt welcome)':
no code for module (newt)
guix package: warning: failed to load '(gnu installer newt)':
no code for module (newt)
random seed for tests: 1552442151
guix package: warning: failed to load '(guix man-db)':
no code for module (gdbm)
name: iproute2
version: 4.20.0
outputs: out
systems: x86_64-linux i686-linux armhf-linux aarch64-linux mips64el-linux
dependencies: bdb@6.2.32 bison@3.0.5 flex@2.6.4 iptables@1.6.2 pkg-config@0.29.2
location: gnu/packages/linux.scm:1254:2
homepage: https://wiki.linuxfoundation.org/networking/iproute2
license: GPL 2+
synopsis: Utilities for controlling TCP/IP networking and traffic in Linux  
description: Iproute2 is a collection of utilities for controlling TCP/IP
+ networking and traffic with the Linux kernel.  The most important of these are
+ `ip', which configures IPv4 and IPv6, and `tc' for traffic control.
+ 
+ Most network configuration manuals still refer to ifconfig and route as the
+ primary network configuration tools, but ifconfig is known to behave inadequately
+ in modern network environments, and both should be deprecated.
relevance: 6

name: ghc-iproute
version: 1.7.5
outputs: out
systems: x86_64-linux i686-linux
dependencies: ghc-appar@0.1.4 ghc-byteorder@1.0.4 ghc-network@2.6.3.6
+ ghc-safe@0.3.17
location: gnu/packages/haskell.scm:2834:2
homepage: https://www.mew.org/~kazu/proj/iproute/
license: Modified BSD
synopsis: IP routing table  
description: IP Routing Table is a tree of IP ranges to search one of them on the
+ longest match base.  It is a kind of TRIE with one way branching removed.  Both
+ IPv4 and IPv6 are supported.
relevance: 4