Tweak script runner so it works on NixOS
I'm not sure I understand this commit. Why does a regular
pwdnot suffice here? I don't think
commandis very portable (I would expect this not to work on Debian's /bin/sh which is dash or on *BSD's /bin/sh).
pwd should probably suffice indeed. But command should be standard and works in NixOS's dash, mksh, fish, or zsh -y