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.
Sorry 'bout that *** This bug has been marked as a duplicate of 139650 ***
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