After sending my message with the trace output attached, I found that meanwhile yet another message had arrived from Steve Isard, containing:
> I have copied the newpop11 of my last message from my kernel 5.8 Ubuntu, > where it was built, but won't run, to an Ubuntu machine running kernel > 5.4, where it runs successfully. Running strace, I see a difference in > the second block of lines where "personality" occurs: I'll try to remember in future to check the inbox before I post anything to popforum. But the duplication may provide a useful cross check between our two environments, Ubuntu and Fedora. The difference between running basepop11 (me) and running pop11 (steve) should not matter because Poplog always starts in basepop11 since the pop11 command is equivalent to basepop11 +startup (getting startup.psv from $usepop/pop/lib/psv where 'startup' saved images for pop11, prolog, lisp, ved, etc. are stored, by default) [Based on an ancient decision taken at Sussex university]. Aaron
