Create new terminal session and create $GOPATH directory:
```
mkdir -p $GOPATH
```
## 3. Download runner sources
```
go get gitlab.com/gitlab-org/gitlab-ci-multi-runner
cd $GOPATH/src/gitlab.com/gitlab-org/gitlab-ci-multi-runner/
```
## 4. Install runner dependencies
This will download and restore all dependencies required to build runner:
```
make deps
```
## 5. Run runner
Normally you would use `gitlab-runner`, in order to compile and run Go source use go toolchain:
```
go run main.go
```
You can run runner in debug-mode:
```
go run --debug main.go
```
## 6. Compile and install runner binary
```
go build
go install
```
## 7. Congratulations!
You can start hacking GitLab-Runner code. If you are interested you can use Intellij IDEA Community Edition with [go-lang-idea-plugin](https://github.com/go-lang-plugin-org/go-lang-idea-plugin) to edit and debug code.