Ubuntu18.04编译Yocto：建立repo环境失败

Repo is a tool built on top of Git that makes it easier to manage projects that contain multiple repositories, which do not need
to be on the same server. Repo complements very well the layered nature of the Yocto Project, making it easier for users to
add their own layers to the BSP.
To install the “repo” utility, perform these steps:

1. Create a bin folder in the home directory.

$ mkdir ~/bin (this step may not be needed if the bin folder already exists)
$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
$ chmod a+x ~/bin/repo

2. Add the following line to the .bashrc file to ensure that the ~/bin folder is in your PATH variable.

export PATH=~/bin:$PATH

其中官方给出的地址需才能用，换成以下地址：

curl http://php.webtutor.pl/en/wp-content/uploads/2011/09/repo > ~/bin/repo