Practically fresh install, both from Devuan (Chimaera) and GDebi, and when opening the latter it says (Taken from internet, my system locale is es_VE):

Software index is broken

This is a major failure of your software management system.    
Please check for broken packages with synaptic, check the file  
permissions and correctness of the file '/etc/apt/sources.list' and    
reload the software information with: 'sudo apt-get update' and   
'sudo apt-get install -f'.

Synaptic does not find broken packages and I checked sources.list and (with my newbie knowledge) I think it's ok. And sudo apt-get update and sudo apt-get install -f returns without issues.

Sorry if there is bad english, it is not my native language.