Improve error messaging when dependency such as eyeD3 is missing

[fredrik]

First off, thanks for a great tool!

I re-compiled caesura 0.26.0 recently on a new machine and got this error:

$ caesura upload 10101010
2025-12-26 12:16:58.118 WARN △ Failed to get transcode details: Failed to get details
A file system error occurred
Permission denied (os error 13)
2025-12-26 12:12:28.272 INFO ○ Uploaded ...

The upload went through, but I didn't immediately understand what the error was about. It took me a few seconds to realise that this was due to the eyeD3 executable missing. Please note that I am not using Docker but am rather running caesura directly.

Could we make the error message clearer here? Ideally I'd like to see "command not found: eyeD3" or similar.

[RogueOneEcho]

There's scope for a lot of improvements here.

The error message should be clearer but it would require an explicit check to see if the dependency exists (such as running which eyeD3)

• Explicitly check if dependency exists before calling, applies to FLAC, SOX etc as well.

The error implementation itself isn't best practice, if I were to revisit it I'd probably:

• replace the errors with Eyre or miette etc

Regarding eyeD3 specifically, the implementation is quite lazy and it could be removed entirely:

• Remove eyeD3 dependency and use lofty to create a better structured description output. Generate descriptions rather than using eyed3 or metaflac #174

I primarily recommend using the Docker image as it bundles all the dependencies solving issues like you've seen.

Unfortunately I don't have much time to dedicate to caesura at present so this will likely go unaddressed but contributions are welcome.

[RogueOneEcho]

@fredrik

I've been looking into this and the behavior you're requesting already exists.

If eyeD3 hits an error when being spawned it's passed to command_error()

caesura/src/dependencies/eyed3/eyed3_command.rs

Line 19 in 4941a22

.map_err(|e| command_error(e, "get details", EYED3))?;

In `command_error() we explicitly check if it's a NotFound error and if so use the message "Could not find dependency: {program}"

caesura/src/utils/errors/error.rs

Lines 28 to 32 in 4941a22

	std::io::ErrorKind::NotFound => Error {
	action: action.to_owned(),
	message: format!("Could not find dependency: {program}"),
	..Error::default()
	},

But in your case it's a permission denied error?
So you may have eyeD3 but for some reason caesura doesn't have the permissions required to execute it?

[fredrik]

Hey, thanks for checking up on this! I'm glad we have support for this already -- we might not need to add what I'm asking for. Still curious what's going on though..

But in your case it's a permission denied error?
So you may have eyeD3 but for some reason caesura doesn't have the permissions required to execute it?

It's not available at all as far as I can tell:

$ eyeD3
-bash: eyeD3: command not found

I'm running this on Whatbox, they're using Gentoo (and are not keen on installing https://packages.gentoo.org/packages/dev-python/eyed3). For what it's worth, this is the uname -a output:
6.6.62-gentoo-whatbox #1 SMP PREEMPT_DYNAMIC Thu Nov 21 19:08:26 UTC 2024 x86_64 AMD EPYC 7702P 64-Core Processor AuthenticAMD GNU/Linux

It's weird that the error handling isn't catching this. I am no Rust expert, but surely this means that the error is something other than std::io::ErrorKind::NotFound.

I'm happy to assist in chasing this down anyway I can.

[fredrik]

So! Looking closer at what other people experience when seeing "os error 13" gave me a hunch.

$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/bin:/usr/lib/llvm/21/bin:/usr/lib/llvm/19/bin:/usr/lib/llvm/18/bin

$ caesura upload 101010
2026-01-30 22:00:00.000 WARN △ Failed to get transcode details: Failed to get details
A file system error occurred
Permission denied (os error 13)
2026-01-30 22:00:00.000 INFO ○ Uploaded

/usr/local/sbin, eh? This is a shared seedbox.

$ ls -l /usr/local/sbin
ls: cannot open directory '/usr/local/sbin': Permission denied

So, trying this:

$ export PATH=/usr/local/bin:/usr/bin:/opt/bin:/usr/lib/llvm/21/bin:/usr/lib/llvm/19/bin:/usr/lib/llvm/18/bin

$ caesura upload 101010
2026-01-30 22:00:00.000 WARN △ Failed to get transcode details: Failed to get details
Could not find dependency: eyeD3
2026-01-30 22:00:00.000 INFO ○ Uploaded ...

Problem solved.

I guess we could possibly improve _ => io_error(error, action),, but I am not sure how.

Feel free to close this discussion!

[RogueOneEcho]

Resolved in fd260aa and 3c57b83

If the eyeD3 dependency isn't found it will now say:

   0.644 WARN △ Unable to add track details to upload description
caesura::commands::upload::upload_action::UploadAction::GetTranscodeDetails

  × Failed to get transcode details
  ├─▶ Failed to get details
  │   ▷ path: [OUTPUT DIRECTORY]
  ├─▶ Failed to start process
  │   ▷ program: eyeD3
  ╰─▶ No such file or directory (os error 2)

And for your case where there is a permission issue:

   0.850 WARN △ Unable to add track details to upload description
caesura::commands::upload::upload_action::UploadAction::GetTranscodeDetails

  × Failed to get transcode details
  ├─▶ Failed to get details
  │   ▷ path: [OUTPUT DIRECTORY]
  ├─▶ Failed to start process
  │   ▷ program: eyeD3
  ╰─▶ Permission denied (os error 13)