We use process builder heavily and sometimes I need to go and see what is there in the Inactive ones. I prefer downloading all flows(including Inactive) and searching in vs code.
I tried the below two commands and both are retrieving only the active version.
sfdx force:source:retrieve --metadatatype=Flow
sfdx force:source:retrieve --metadatatype=FlowDefinition
How do I download the active and inactive versions?