I have tried ddd on macOS Mojave and it crash on start<.
ddd example
Error: Unresolved inheritance operation
Xt error (Unresolved inheritance operation).
Oops! You have found a bug in DDD.
If you can reproduce this bug, please send a bug report
DDD 3.3.12 (i386-apple-darwin18.0.0) gets Xt error
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* The contents of the `~/.ddd/log' file as generated by this session.
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