That's the curse on the Unix world. At least FreeBSD, NetBSD (OpenBSD not by design, but that's understandable because of security) have their compat libraries on plus some of them (even GTK1) in their ports. On 9front, I just adapted Russ Cox' Xword (some crossword player for XWord files, it has a converter from Across Lite Puz files to Xword) for modern times, barely a few lines changes in some drawing function for software made for Plan9 4ed or close.

PD: Guix can do the same as fbsd and nbsd because, well, setting up an isolated environment with time-bound tools it's basically what Guix was born for, reproducibility. Scientific repo for a paper must be run point to point as we had a Slackware setup with Slackbuilds in 2007? That's the point of Guix. You would say... docker. But docker it's overkill.