Why change this line?

i think it isgo-versions in line 7 and go-version here, so it didn't work.

Ah, yes, so here's why I renamed (and why it was somewhat easy to overlook the problem);

Originally, the matrix looked like (simplified);

strategy:
  matrix:
    go-versions: [1.12.x, 1.13.x, 1.14.x]
steps:
- name: Install Go
  uses: actions/setup-go@v1
  with:
    go-version: ${{ matrix.go-version }}

I haven't done a lot with GH Actions yet, so when reading the above, I made the incorrect assumption that was how GH actions handled matrix values;

• matrix -> go-versions being plural (because it's a list), and
• with -> go-version singular, because it gets assigned a value from the matrix.

Clearly, I was wrong there (and the with: value must have the same name as the value in the matrix:).

When looking for the problem, I went to the GitHub repo of the action; https://github.com/actions/setup-go/blob/v2.1.3/README.md#usage. Comparing those examples with what we had;

• Perhaps it was because we didn't explicitly add quotes around the values in the 1.12.x (recalling the dreaded YAML time issue docker/compose#103 issue when specifying port-mappings in compose)
• Perhaps it didn't support the .x suffixes? (planning on opening a ticket or PR in that repository to add a section explaining what formats are accepted)
• Perhaps it was a bug in v1, fixed in v2?
• Perhaps it was the name (go-versions versus go)?

And that's when I found the difference (plural versus singular).

@AkihiroSuda I can rename to go-version if you prefer; I used go (as in the example) because I thought it was less likely for someone to rename go to gos (plural), and re-introduce the bug, but I'm not really attached to the name