CLI app discovery broken under certain circumstances (utmctl symlink)

[lishaduck]

Describe the issue
I don't have admin permissions, but I do have homebrew, so I installed UTM via homebrew with --appdir=~/Applications/. utmctl, however, errors as follows:

2024-08-15 20:28:29.203 utmctl[28511:15501686] Can't find app with file path /Applications/UTM.app
Error: Application not found.

I filed an issue over at Homebrew/homebrew-cask#182568, and I was directed to file an issue here.

Configuration

• UTM Version: 4.5.3 (I'm about to upgrade, I'll update it if it fixes it)
• macOS Version: 14.6.1
• Mac Chip: M1

Crash log
n/a

Debug log
n/a

Upload VM
n/a

---

I haven't written Swift in ages, but I'm happy to try to fix it.

[osy]

How are you calling utmctl?

[lishaduck]

How are you calling utmctl?

Oh, silly me 😅

$ utmctl list
2024-08-27 11:05:23.455 utmctl[37164:17429559] Can't find app with file path /Applications/UTM.app
Error: Application not found.

[osy]

Can you run ls -l $(which utmctl) and paste the output?

[lishaduck]

lrwxr-xr-x  1 username  admin  58 Aug 27 11:00 /opt/homebrew/bin/utmctl -> /Users/username/Applications/UTM.app/Contents/MacOS/utmctl

[osy]

I've been playing around with this and it seems like it's actually not possible for a sandboxed CLI app to know what's its own real path is.

    /// Find the path to UTM.app
    private var utmAppUrl: URL {
        if let executableURL = Bundle.main.executableURL?.resolvingSymlinksInPath() {
            let utmURL = executableURL.deletingLastPathComponent().deletingLastPathComponent().deletingLastPathComponent()
            if utmURL.lastPathComponent == "UTM.app" {
                return utmURL
            }
        }
        return URL(fileURLWithPath: "/Applications/UTM.app")
    }

This returns the default path if it cannot determine the correct path. However, when you symlink, Bundle.main.executableURL returns nil and Bundle.main.bundleURL returns nil as well. CommandLine.arguments.first returns a sandboxed path /Users/username/Library/Containers/com.utmapp.utmctl/Data/utmctl. I don't know any other way to do it.

The workaround is if you add /Users/username/Applications/UTM.app/Contents/MacOS to your PATH variable. For example by creating a new entry in /etc/paths.d/

[lishaduck]

I've been playing around with this and it seems like it's actually not possible for a sandboxed CLI app to know what's its own real path is.

That's too bad, but thanks for investigating!

CommandLine.arguments.first returns a sandboxed path /Users/username/Library/Containers/com.utmapp.utmctl/Data/utmctl.

I never knew what ~/Library/Containers contained, and now I do, so at least I learned something :)

The workaround is if you add /Users/username/Applications/UTM.app/Contents/MacOS to your PATH variable.

Yeah, I figured that'd probably end up being the solution, though I'd rather it not be (my .zshrc file is complicated enough as it is, but at least I know where to fix it)
I assumed that if vscode could do it, it couldn't be too hard, but vscode isn't sandboxed. For that matter, why is UTM sandboxed? It's not distributed via the mas.

[osy]

It is indeed distributed on MAS. And also because of the added security (if there's a QEMU bug, it won't automatically be able to rw your entire drive).

[lishaduck]

It is indeed distributed on MAS.

Oh, yeah 🤦‍♂️

And also because of the added security (if there's a QEMU bug, it won't automatically be able to rw your entire drive).

I'm glad to hear that 😅