bug#29881: guix system reconfigure fails if config.scm contains LUKS mapped-devices

[Diego Nicola Barbato]

Hello Guix,

When running `guix system reconfigure /etc/config.scm' as root I get the
following error:

guix system: error: failed to load '/etc/config.scm':
/etc/config.scm:24:9: /etc/config.scm:24:9: In procedure allocate-struct: Wrong 
type argument in position 2: 3

This error appears for the first time in commit
4ca90ff5976434a2b6e758df38df54387ae70c1b.  On line 24 of my config file
I have declared a mapped device of type luks-device-mapping.  If the
config file does not contain any mapped-devices declaration `guix system
reconfigure' works as expected (checked in a VM).

I run GuixSD on a x86_64 machine.

Greetings

Diego N. Barbato