fix: quote program and args in debug message from cmd::cmd(..)

[ktetzlaff]

Problem

While trying to understand an issue with the value of VISUAL in mise -v tasks edit <task> (see #9731, already addressed by PR #9752), I found the debug! message generated by cmd::cmd(..) to be less helpful than it could be. With VISUAL='cat -n', the following information got logged:

...
DEBUG $ cat -n /home/kt/work/oss/mise/tasks.toml
Error:
   0: No such file or directory (os error 2)
...

Here, cat -n was interpreted as the program to execute. However, the DEBUG ... line, doesn't show that.

Solution

Call shell_escape::escape(..) on program and args when generating the debug! message. This changes the logged information to:

...
DEBUG $ 'cat -n' /home/kt/work/oss/mise/tasks.toml
Error:
   0: No such file or directory (os error 2)
...

This hopefully helps to understand the reason for the following error message from duct::cmd(..)).

---

Note: The error reported by duct::cmd(..):

Error:
   0: No such file or directory (os error 2)

also leaves room for improvement. This was already discussed in issue 109: Include the command that failed in the error from 2023 in the duct.rs repository. A fix for this issue would potentially solve the problem addressed by this commit/PR. But so far, nobody stepped up to provide that fix.

[greptile-apps]

Greptile Summary

This PR improves the cmd() debug message in src/cmd.rs by applying shell_escape::escape to both program and args, so values like cat -n appear as 'cat -n' in logs and are clearly distinguishable from a normal two-token invocation. The code is also simplified by chaining program and args into a single iterator before mapping.

• shell_escape::escape is applied uniformly to both the program path and every argument, using a single chained iterator instead of two separate variables.
• shell_escape was already a declared dependency (Cargo.toml line 173), so no new crate is introduced.

Confidence Score: 5/5

Safe to merge — the change is limited to a single debug log line with no effect on program execution or error handling.

The only modification is how the debug string is formatted before being passed to debug!. The duct::cmd(program, args) call is unchanged, so runtime behaviour is identical. The shell_escape crate is already a dependency, and the iterator refactor is straightforward.

No files require special attention.

Important Files Changed

Filename	Overview
src/cmd.rs	Refactors the debug display in cmd() to apply shell_escape::escape to both program and args, making ambiguous programs like 'cat -n' distinguishable from a normal two-token invocation in the log output.

_{Reviews (3): Last reviewed commit: "fix: quote `program` and `args` in debug..." | Re-trigger Greptile}

[gemini-code-assist]

Code Review

This pull request refactors the construction of the display_command string in src/cmd.rs to use an iterator chain for debug logging. However, the current implementation will fail to compile due to a type mismatch between &PathBuf and &OsString in the chain method. Feedback also highlights that the string is constructed even when debug logging is disabled and that the quoting mechanism does not correctly handle arguments containing single quotes.

[gemini-code-assist]

This code will fail to compile due to a type mismatch in the chain call. std::iter::once(&program) yields &PathBuf, while &args (as an iterator) yields &OsString. The chain method requires both iterators to have the exact same item type. You can fix this by explicitly converting both to &OsStr using .as_os_str().

Additionally, note that this implementation constructs the display_command string regardless of whether the debug log level is enabled, which is slightly inefficient. Also, the quoting is naive and doesn't handle arguments containing single quotes (e.g., it's a file becomes 'it's a file', which is invalid shell syntax).

Suggested change

	let display_command = std::iter::once(&program)
	.chain(&args)
	.map(|s| format!("'{}'", s.to_string_lossy()))
	.collect::<Vec<_>>()
	.join(" ");
	let display_command = std::iter::once(program.as_os_str())
	.chain(args.iter().map(|s| s.as_os_str()))
	.map(|s| format!("'{}'", s.to_string_lossy()))
	.collect::<Vec<_>>()
	.join(" ");

[ktetzlaff]

This code will fail to compile ...

It compiles (and runs) just fine.

Additionally, note that this implementation constructs the display_command string regardless of whether the debug log level is enabled, which is slightly inefficient.

Yes, but the original code did the same. So I did not see a reason to change that.

Also, the quoting is naive and doesn't handle arguments containing single quotes (e.g., it's a file becomes 'it's a file', which is invalid shell syntax).

Fixed by using shell_escape::escape(..) instead of format!(..).