How to add multiple build tasks in Visual Studio Code?

I am trying to use Visual Studio Code to build a Haxe project. I would like to have two build commands, one to build with the -debug option, and one to build without it. Here is my tasks.json file code:

{
"version": "2.0.0",
"tasks": 
[
    {
        "type": "lime",
        "command": "test",
        "group": {
            "kind": "build",
            "isDefault": true
        }
    },
    {
        "label": "build: flash",
        "command": "haxelib",
        "group": {
            "kind": "build",
            "isDefault": true
        },
        "args": [
            "run",
            "lime",
            "build",
            "flash",
        ],
        "problemMatcher": [
            "$haxe-absolute",
            "$haxe",
            "$haxe-error",
            "$haxe-trace"
        ]
    },
    {
        "label": "debug: flash",
        "command": "haxelib",
        "args": [
            "run",
            "lime",
            "build",
            "flash",
            "-debug",
            "-Dfdb"
        ],
        "problemMatcher": [
            "$haxe-absolute",
            "$haxe",
            "$haxe-error",
            "$haxe-trace"
        ]
    }
]
}

This gives me two tasks named "lime: test flash -debug" and "build: flash". The "lime: test flash -debug" command works fine, but when I run "build:flash" nothing happens. The haxelib command shows up in the terminal, but nothing pops up. I've read both the tasks documentation here and the tasks.json schema here and I still can't figure out how to do this. Can anyone tell me how to do this? Thanks.