`nixos-option` evals the description and the '`' is used to
define shell commands.
Due to this, the following error appears:
```
$ nixos-option services.postgresql.superUser
Value:
"root"
Default:
"root"
Description:
/run/current-system/sw/bin/nixos-option: line 294: root: command not found
/run/current-system/sw/bin/nixos-option: line 294: postgres: command not found
NixOS traditionally used as superuser, most other distros use .
From 17.09 we also try to follow this standard. Internal since changing this value
would lead to breakage while setting up databases.
```
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