看起来我试图执行错误的纱线，因为在我的 Ubuntu 18.04 上运行 sudo apt install yarn 给了我来自 cmdtest 的纱线.

It looks like that I was trying to execute the wrong yarn, because simply running sudo apt install yarn on my Ubuntu 18.04 gave me yarn from cmdtest.

所以我通过卸载解决了:

So I solved by uninstalling it:

sudo apt remove yarn

并按照官方网站的说明进行安装，在我的情况下(Ubuntu 18.04) 如下:

And by installing it as the official website explains, which in my case (Ubuntu 18.04) it was the following:

curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list

sudo apt update && sudo apt install yarn

yarn