Error attempting to get summary for Canon EOS 4000D: Error (-60: 'Could not lock the device')

Hi

I have just acquired a cannon EOS 4000D slr camera and wanted to use 
gphoto2 to connect to it.

My system:
cat /etc/*-rel*
DISTRIB_ID=Trisquel
DISTRIB_RELEASE=8.0
DISTRIB_CODENAME=flidas
DISTRIB_DESCRIPTION="Trisquel GNU/Linux 8.0, Flidas"
NAME="Trisquel GNU/Linux"
VERSION="8.0, Flidas"
ID=trisquel
ID_LIKE=debian
PRETTY_NAME="Trisquel GNU/Linux Flidas (8.0)"
VERSION_ID="8.0"
HOME_URL="https://trisquel.info/"
SUPPORT_URL="https://trisquel.info/wiki"
BUG_REPORT_URL="https://trisquel.info/project/issues"

$ uname -a
Linux technoethical-t400s-b9d0 4.19.139-gnu #1.0 SMP Tue Sep 27 12:35:59 
EST 1983 x86_64 x86_64 x86_64 GNU/Linux

-------------------------------

The default version of gphoto2 for my system is 2.5.9 and this did not 
include the 4000D in the supported list, so I downloaded the source for 
the latest versions of liggphoto2 (2.5.25) and gphoto2 (2.5.23), 
configured and built them.

This done I can plug the camera in and run:
$ gphoto2 --auto-detect
Model                          Port
----------------------------------------------------------
Canon EOS 4000D                usb:002,009

and it detects the camera fine.

However when I try to do anything with it I get the following:
$ gphoto2 --summary

*** Error ***
An error occurred in the io-library ('Could not lock the device'): 
Camera is already in use.
*** Error (-60: 'Could not lock the device') ***

For debugging messages, please use the --debug option.
Debugging messages may help finding a solution to your problem.
If you intend to send any error or debug messages to the gphoto
developer mailing list <[email protected]>, please run
gphoto2 as follows:

     env LANG=C gphoto2 --debug --debug-logfile=my-logfile.txt --summary

Please make sure there is sufficient quoting around the arguments.

Anyone any idea what is happening here ? My searches have shown other 
people have has similar messages, but I have not seen a solution for it.