This is a minor issue that I picked up while testing my Python interface to libgphoto2 on the main (1.0.0) branch. The po/exiv2.pot file on the main branch was last updated 3 years ago, compared to 4 months ago on the 0.28.x branch.

Could it be automatically updated when building exiv2 (if NLS support is turned on) like the .po files are?