Choosenim uses @dom96's untar package. [https://github.com/dom96/choosenim/blob/master/src/choosenim/utils.nim#L75](https://github.com/dom96/choosenim/blob/master/src/choosenim/utils.nim#L75)
[https://github.com/dom96/untar](https://github.com/dom96/untar) There's also nimarchive which can do this.
