Single-quoted solitary item in for loop spuriously triggers SC2041 but not SC2043

[antifuchs]

For bugs

• Rule Id (if any, e.g. SC1000): SC2041
• My shellcheck version (shellcheck --version or 'online'): online
• I tried on shellcheck.net and verified that this is still a problem on the latest commit
• It's not reproducible on shellcheck.net, but I think that's because it's an OS, configuration or encoding issue

For new checks and feature suggestions

• shellcheck.net (i.e. the latest commit) currently gives no useful warnings about this
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

#!/usr/bin/env bash

for dev in '/dev/disk/by-uuid/28DD-A89E'; do
  echo "$dev"
done

Here's what shellcheck currently says:

Line 3	SC2041: This is a literal string. To run as a command, use $(..) instead of '..' . 

Here's what I wanted or expected to see:

I would not expect this to warn about SC2041, but SC2043. The following snippet where a second single-quoted element is iterated over does not warn about SC2041 (and, correctly, not about SC2043):

#!/usr/bin/env bash

for dev in '/dev/disk/by-uuid/28DD-A89E' 'foo'; do
  echo "$dev"
done

and neither does the following with double quotes (it does warn about SC2043, as expected):

#!/usr/bin/env bash

for dev in "double-quoted"; do
  echo "$dev"
done

[ormaaj]

That word doesn't require quotes anyway so... maybe it's just guessing that it's a command-in-a-string for some reason. Erroneous if so.

This is just silly and hopefully not the actual rationale. There are several noisy and not super useful single-quoting warnings similar to this - where it tries to guess that the content of a single-quoted word was supposed to be something else.

[iFreilicht]

This is indeed quite annoying, especially when auto-generating scripts, see nix-community/disko#868

In my case, it's also purely about strings that all start with /dev, so I'd be fine if there was just a short list of exceptions that prevented this from triggering. Something like ls or /bin/bash could indeed be a command.