This bug can be closed. No longer an issue with KDevelop 5.6.2. Fixed in KDevelop git commit fa83c76b133a52c8ce0e7af0aa8c060fadaa8536
Background: Debian and Ubuntu (and others?) have unique clang --version output. KDevelop tries a few different ways to determine the clang include directory. The most successful method seems to be matching on the output of the 'clang --version' output (which the developers recognize as unsafe ).
