Only use ASCII with nix output messages

[unode]

I don't know when this change was introduced but it became more apparent as of nix-1.11.7.

Nix makes use of ‘%1%’ for displaying paths.
When running nix commands (e.g. in cron-jobs) I now get output like this:

path �/nix/store/00ai2akd0m5cnzxn6z68pd8lnhxz2zg5-python3.5-PythonEnv.drv� is not in the Nix store at /nix/var/nix/gcroots/system/bin/nix-shell line 263.

The same character is also shown as _ or some other symbol when running inside screen or tmux. This sometimes gets in the way when copy-pasting a path.

The garbled output is likely related to encoding/locale issues but I was wondering if using ASCII backticks instead of ‘ ’ would be an acceptable solution.

Your thoughts?

[veprbl]

Some context:
#1140
215b70f

[unode]

@veprbl thanks. Closing as duplicate and moving discussion to #1140