ccgnu2-config(1) on Linux
The text 7ef21e2be178, as Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze) shipped it. The page shows this text now.
script to get information about the installed version of libcommoncpp2