Support tip?

I looked through the installer.js script and it looked to me like only tags from https://github.com/golang/go/tags are supported as valid versions to install.

I would imagine that some users would also want to test their Go programs against tip to ensure that upcoming language changes/additions don’t break.

Go even provides a way to install tip via https://godoc.org/golang.org/dl/gotip (once you have a single Go version installed that is).

What do you think?

[tsatke]

I would like being able to use it in go_version: [1.11, 1.12, 1.13, tip]

[zikaeroh]

For now, I’ve done the following:

- name: Install Go
  if: matrix.go != 'tip'
  uses: actions/setup-go@v2
  with:
    go-version: ${{ matrix.go }}

- name: Install gotip
  if: matrix.go == 'tip'
  run: |
    git clone --depth=1 https://go.googlesource.com/go $HOME/gotip
    cd $HOME/gotip/src
    ./make.bash
    echo "GOROOT=$HOME/gotip" >> $GITHUB_ENV
    echo "$HOME/gotip/bin:$PATH" >> $GITHUB_PATH

Because I’m lazy I used gotip rather than cloning directly (EDIT: Updated to just clone and build as @mvdan suggested; it’s faster), but in addition to modifying $PATH, $GOROOT has to get set for some reason to get the correct $GOTOOLDIR (even though it should be inferred; probably some existing environment variable). No need to run setup-go to bootstrap this stage, since the builders come with a Go version already installed. Takes about 3 minutes to build.

I haven’t tested this with anything but a Linux host. It probably needs a shell option to say it’s a bash script. Probably could be simplified as well.

(EDIT: updated 2021-10-17 for new versions and GHA changes 😄)