A slight typo in the function generating the usb usermap for libgphoto2-2.2.1 makes print-camera-list spit out a help message instead of the actual usermap. I presume that depending on the CONFIG_PROTECT settings, this erroneous file could overwrite the good usermap. The error is on line 132, where there is one hyphen too many in the usb-usermap command.
Created attachment 91195 [details, diff] Patch for the typo
*** Bug 139648 has been marked as a duplicate of this bug. ***
*** Bug 139649 has been marked as a duplicate of this bug. ***
Fixed. Sorry about that.