First off, I'm aware (now) that the ulimit command doesn't accept a "--help" option. That's not the issue (though I wouldn't mind if it did).
My OS: Linux Mint 17.3 on x86_64. I built both versions 4.3.30 and 4.4-beta from source with default options with gcc 4.8.4. $ uname -a Linux bomb20 3.16.0-38-generic #52~14.04.1-Ubuntu SMP Fri May 8 09:43:57 UTC 2015 x86_64 GNU/Linux $ /_opt/apps/bash-4.3.30/bin/bash -c 'echo $BASH_VERSION ; ulimit --help' 4.3.30(1)-release /_opt/apps/bash-4.3.30/bin/bash: line 0: ulimit: --: invalid option ulimit: usage: ulimit [-SHabcdefilmnpqrstuvxT] [limit] $ /_opt/apps/bash-4.4-beta/bin/bash -c 'echo $BASH_VERSION ; ulimit --help' 4.4.0(1)-beta /_opt/apps/bash-4.4-beta/bin/bash: xrealloc: ./ulimit.def:382: cannot allocate 4294967296 bytes (8590045184 bytes allocated) $ -- Keith Thompson <keith.s.thomp...@gmail.com>
