Posting here because the Jira instance does not allow guests to create issues (??). Or perhaps I could not figure out how to create an issue there 
Default /usr/share/mender/inventory/mender-inventory-provides installed from the Debian repository (v4.0.4) does not respect the DeviceTypeFile field in mender.conf. This script should either be able to find the correct path or it should be mentioned in the documentation.