SUMMARY

After updating KDE Frameworks to 5.70.0 .desktop link files for terminal programmes (Terminal=true) result in a message saying "konsole" can't be found. Opening a "konsole" from GUI menu works fine, so binary is available.

Journal error text:
'Internal program error. QStandardPaths::findExecutable couldn't find "konsole" but our own logic found it at "/usr/bin/konsole".'

Linking to GUI apps works anyway.

Seems related to this bugfix commit:
https://bugs.kde.org/show_bug.cgi?id=415567

The detection logic was changed and exactly the above mentioned error text was added.

+ qWarning() << "Internal program error. QStandardPaths::findExecutable couldn't find" << executable << "but our own logic found it at" << candidate << ". Please report a bug at https://bugs.kde.org";

STEPS TO REPRODUCE
Create a .desktop link file ("[Desktop Entry]") with run in terminal option (binary file or script doesn't matter).
Run the Link by clicking on it. Error message appears.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 32
KDE Frameworks Version: 5.70.0
Qt Version: 5.13.2