dosemu2 in Linux; syncpipe[0] < MAX_FD' failed, cpu exception in dosemu code outside of VM86

I run an old-school bulletin board (online system), and I've been using 
dosemu2 in Linux to run 16-bit DOS online games ("door games").  I've 
noticed that when that computer has been running a while (it could be after 
just a few days, or a week or more), dosemu2 starts failing when it runs, 
and it gives this error:

dosemu.bin: ./build/../src/base/misc/ioctl.c:306: void ioselect_init(void): 
Assertion `syncpipe[0] < MAX_FD' failed.ERROR: cpu exception in dosemu code 
outside of VM86()!Aborted (Signal sent by tkill() 441761 1000)ERROR: Please 
install gdb, update dosemu from git, compile it with debuginfo and make a 
bug report with the content of ~/.dosemu/boot.log 
athttps://github.com/dosemu2/dosemu2/issuesPlease provide any additional 
info you can, like the test-cases,URLs and all the rest that fits.

When it happened most recently, I was using dosemu2 
2.0~pre9-8412-b15ad8fad+202312111916~ubuntu22.04.1.  I'm wondering what 
might cause this error?

Eric