Or in other words, Ubuntu 16.(04|10) doesn't support sh6 (and its external goto utility)...
It should but doesn't; it seems to be an Ubuntu lseek(2) problem (see Description for more info). In any case, when building / compiling sh6 from osh-current on this particular system, you will get a cpp error referring you to this blog post (see this commit for more info). OK. So, now what?
In short, there are 2 options:
Don't use Ubuntu 16.xx .. Use OpenBSD instead;
If you must use Ubuntu 16.xx but also want to run sh6 (and goto), simply run osh instead;
Number 1 - Pretty self explanatory. The last time I used Ubuntu for anything of consequence (except for debugging the problem described here on Ubuntu 16.10 - I don't trust Ubuntu1, BTW), it was Ubuntu 10.04. LTS. I do everything with OpenBSD these days; it's where the Osh Project was born after all, and everything works perfectly here. But Ubuntu 16.xx? Forget it! Well, except osh works fine there.. So...
Number 2 - Simply build & install osh via the oshall & install-oshall targets, and then run it instead of sh6 and its external utilities. If you want to invoke it by typing sh6, just make sh6 a symbolic link to osh. Done. You should be ready to roll now.
Ubuntu 16.(04|10) Problems
Further details about why sh6 (and goto) no longer work on this Ubuntu release .. For the record, it has been reported that they work fine on 14.04 ...
It's not just an lseek(2) problem though. Specifically, it's that Ubuntu 16.(04|10) is losing the correct offset set by goto on the standard input. The tests I did pointed to some sort of problem with fork(2)/lseek(2)/execve(2). <-
But let's pin it down more precisely... Somewhere in the Ubuntu nightmare, it's barfing up a lung in the following transition:
child process (goto) <-> execve(2) <-> parent process (sh6)
... See http://v6shell.org/ubuntu-16 for details I collected while debugging this Ubuntu 16.(04|10) issue / problem .. But I really can't afford the time to dig any further since Ubuntu isn't a BSD operating system .
Thanks & Enjoy & Cheers ! =^)
systemd is a disease ( the name even says so, haha! X^D System D == System Disease (^; ) in my eyes; it is the antithesis of everything that UNIX is supposed to be. As such, I cannot trust any so-called UNIX-like operating system using it. This includes Ubuntu, which I never really trusted in the first place. ↩