Regarding nbgv.json

[AArnott]

Why does the action produce a nbgv.json file?
Is the root directory of the user's source tree the right place to create such a file, or does GitHub Actions define an artifacts directory that would be more appropriate?

[ctaggart]

nbgv.json is not needed. I recommend removing it:
https://github.com/AArnott/nbgv/blob/10e1135ef1d89a3db40c2eb571794f981411c326/src/main.ts#L28-L34

I'm not that familiar with nbgv cloud --all-vars, but if it is for setting the cloud variables, may be we should try setting them with it. The format is ##[set-env name=NBGV_SemVer2;]0.7.17-ga79541b. I'll try echoing that format to verify that it works. You could then avoid creating and reading the json and switch the command.

[AArnott]

Already done here: dotnet/Nerdbank.GitVersioning#378

I'd appreciate you testing it though!

[ctaggart]

Yes, just echoing that to stdout works.

    - run: echo "##[set-env name=NBGV_SemVer2;]0.7.17-ga79541b"
    - run: echo "NBGV_SemVer2 $NBGV_SemVer2"

https://github.com/ctaggart/froto/runs/196810208

If you want me to test a beta build, you can add version and source input options to pass in here if set:
https://github.com/AArnott/nbgv/blob/10e1135ef1d89a3db40c2eb571794f981411c326/src/main.ts#L10