When I installed gPhoto2 using gPhoto2-updater after removing an existing apt-derived gPhoto2 with reference to this article, I was able to execute the commands which @craig presented and the configuration of gPhoto2 became the same.
It seems to be better to use gPhoto2-updater than to install it with apt.
But I wonder why gPhoto2-updater has not been updated. I wonder why we have to separate gPhoto2-updater and apt.
add 20/10/04
As usual, “gphoto2 --set-config-index shutterspeed=10” did not work properly, but the error message changed.
Previously.
*** Error (-110: 'I/O in progress') ***
Present.
*** Error ***
Shutterspeed not found in configuration tree.
*** Error (-1: 'Unspecified error') ***