Just to beat a dead horse I did some investigation into this.
The older bundled lib i mentioned earlier crapped out again.
However, I know it worked pretty well back in the day and even coded some areas for it. Turns out that was on an old Gateway running Ubuntu
14 on a 32 bit system. Under my current Linux Mint 19.2 64 bit the older bundle works sporadically at best as the OP pointed out.
However, I fired up the old box and recompiled it and got it running. It was a pain in the ass then and it is now. I forgot you had to manually copy the erq and indent utility files from their respective directories after they were compiled (make install-utils command didn't) and move them to the bin directory holding the ldmud executable file. That wasn't really clear from the instructions. Once done, just issue the ./ldmud <whateverport> command and the thing works.
The good news is that once everything was compiled and running on the old box I just copied the whole shebang (the whole mud directory) to my current computer and low and behold it runs well. I mean, it's not the latest driver and all, but it runs the heaven7_4a2_pkg-004 mud lib. Just to be clear I am using the executable files created on the older machine. Since everything is built into the executable I had to recreate the directory structure on the newer box so the program could find the mudlib. Trying to recompile from scratch was a no-go.
So, if one just wants to fire up the Heaven7 lib and play with it there is a way to do it so that it runs stably. But getting it to run to make it into an actual robust playable mud? I don't know - seems like a stretch. Also, even the mudlibs that are built for the ldmud driver are having a mess of problems with memory allocation resulting in segmentation faults as seen in some of their recent forum posts.
Oh yeah, you can always run the dos version of heaven7 under dos box....works great!