I had a look at Issue #23 and I think I've found the problem.
It looks like the vdaubry was attempting to use SimpleCommand::Errors#add_mutliple_errors to copy values over from another SimpleCommand::Errors object.
Attempting to do the same thing resulted in the same error he reported on my end.
In the past I've used Array.wrap from ActiveSupport to fix this type of issue, but as we don't have ActiveSupport as a dependency (and probably shouldn't) I ported the logic over.
I had a look at Issue #23 and I think I've found the problem.
It looks like the vdaubry was attempting to use SimpleCommand::Errors#add_mutliple_errors to copy values over from another SimpleCommand::Errors object.
Attempting to do the same thing resulted in the same error he reported on my end.
In the past I've used Array.wrap from ActiveSupport to fix this type of issue, but as we don't have ActiveSupport as a dependency (and probably shouldn't) I ported the logic over.
Added tests to verify the fix.