On Sunday, 21 April 2024 at 08:44:38 UTC, alex wrote:

You can do this using configurations. Whichever you list first will be the default. Then you can use -c configName or --config=configName to build the other one.

You'll want to exclude one of the main functions when building the configuration to which it doesn't belong. You can do that with version specifications (e.g., add a cli version in the cli configuration, then vesrion(cli) void main {...} in the code). Alternatively, if the files the main functions are in are self-contained, then you can just exclude the one you don't need in each configuration with the excludeSourceFiles directive.

Configurations:
https://dub.pm/dub-guide/recipe/#configurations

On Sunday, 21 April 2024 at 16:41:08 UTC, Mike Parker wrote:

Thanks, that really helped me.

For everyone who has the same trouble I can attach my working solution based on sub packages and configurations. Here is my dub.json:

{
    "name": "cool",
	"subPackages": [
        {
            "name": "app",
            "sourcePaths": ["source"],
            "mainSourceFile": "source/app.d",
            "targetType": "executable",
			"configurations": [
				{
					"name": "app",
					"targetType": "executable",
					"versions": ["app"]
				}
			]
        },
        {
            "name": "cli",
            "sourcePaths": ["source"],
            "mainSourceFile": "source/cli.d",
            "targetType": "executable",
			"configurations": [
				{
					"name": "cli",
					"targetType": "executable",
					"versions": ["cli"]
				}
			]
        }
    ]
}

Main functions:
app.d:

  version(app)
  void main() {...}

cli.d:

  version(cli)
  void main() {...}

And here how I run/build it:

> dub run :cli
> dub run :app

OR

> dub build :cli
> dub build :app

During building, it will create executable like "{name_of_project}_app" or "{name_of_project}_cli".