All errors in functions in the
(geda config) are reported using
one of two keys:
config-error is signalled,
data part of the error
arguments is a list containing one of the following symbols:
The text being parsed was in an unknown encoding.
The configuration data wass ill-formed.
A requested configuration key was not found.
A requested configuration group was not found.
A configuration value could not be parsed into the requested format.