Everyone, I have made a new installer to install 2.6.0 for MacOS. Please test. Note... After you install this you are going to execute /opt/macports-denemo/bin/denemo. Let me know if you have any questions or problems. This has been compiled in Big Sur and will likely run in Big Sur or anything newer. Also, This does not contain lilypond. You are going to have to install that separately and point denemo to it. Here is the link to the download: https://www.denemo.org/~jjbenham/darwin/denemo-2.6.0_1.mpkg
Thanks, Jeremiah