maker-dmg fails when run in parallel

Pre-flight checklist

[X] I have read the contribution documentation for this project.
[X] I agree to follow the code of conduct that this project uses.
[X] I have searched the issue tracker for a bug that matches the one I want to file, without success.

Electron Forge version

7.3.0

Electron version

N/A

Operating system

macOS 14.3

Last known working Electron Forge version

It broke in 7.0.0

Expected behavior

Expect electron-forge make -- --arch=x64,arm64 to build both x64 and arm64 versions of the app.

Actual behavior

Both x64 and arm64 make steps fail. with the error Target already exists node_modules/appdmg/lib/appdmg.js:81:53

Steps to reproduce

electron-forge make -- --arch=x64,arm64

{
    name: "@electron-forge/maker-dmg",
    config: {
        debug: true,
        overwrite: true,
    },
    platforms: ["darwin"],
}

Additional information

For context it'll be helpful to read through this PR that changed how makers are run. https://github.com/electron/forge/pull/3363

I dug into this a bit. the specific target error comes from appdmg.js:81:53

On a run through with just one target that succeeded:

console.log("Target step started", global.target); at the start of that shows

[REDACTED]/desktop/out/make/OurAppName.dmg for both of the builds that are happening simultaneously

I took a look at the electron code that calls into that @electron-forge/maker-dmg/src/MakerDMG.ts output on line 21 is the one used as the target. forgeDefaultOutPath is fine though. For example: [REDACTED]/desktop/out/make/OurAppName-1.2.3-arm64.dmg

dmgConfig is

overwrite = true
name = "OurAppName"
debug = true
icon = "assets/resources/icon.icns"
background = "assets/resources/installBackground.png"
appPath = "[REDACTED]/desktop/out/OurAppName-darwin-arm64/OurAppName.app"
out = "[REDACTED]/desktop/out/make"

Execution goes into the conditional (if !this.config.name)

I think this could probably be fixed by adding the targetArch to the outPath.

I plan on submitting a PR to fix this soon.

electron / forge