I installed kdiff3 on Kubuntu 22.04 LTS and noticed it is quite chatty:
$ kdiff3 --version
kdiff3 1.9.5 (64 bit)
$ touch file1 file2
$ kdiff3 file1 file2
org.kde.kdiff3: "Loading A: .../file1"
org.kde.kdiff3: "Loading B: .../file2"
org.kde.kdiff3: "Diff: A <-> B"
org.kde.kdiff3: "Linediff: A <-> B"
org.kde.kdiff3: Enter: calcDiff3LineListUsingAB
org.kde.kdiff3: Leave: calcDiff3LineListUsingAB
These useless info messages are written to stderr. Can I suppress them without loosing any real error messages? I don't remember having seen them in older versions of Ubuntu.