x/vgo: netrc failing to load on Windows, possibly in wrong place

[rsc]

On Windows $HOME/.netrc is the wrong path; at the least there's no $HOME.
We should find out what the canonical path is on Windows and use that.

See #23955 (comment) by @doxxx.

[doxxx]

On Windows, the equivalent of $HOME is $USERPROFILE. I do also have a HOME env var defined, pointing at the same location as USERPROFILE. I've created a _netrc file in that location with these contents:

machine api.github.com
login doxxx
password TOKEN

I've verified using Windows Subsystem for Linux that vgo with a $HOME/.netrc containing the above does not encounter the Github rate limits even after multiple invocations of vgo get -u in quick succession.

[doxxx]

I just tried renaming the _netrc to .netrc in Windows and it appears to be working with the contents I described above. I had tried .netrc originally, but maybe I got the format wrong at the time?

To summarize, for this to work:

• .netrc must be created in the user's profile directory (e.g. C:\Users\Gordon)
• Line endings don't matter, both CRLF and LF work.
• There must be a HOME env var containing the path to the user's profile directory. It doesn't work if this is not defined.
• The .netrc must use your Github username for the login and your generated Github auth token for the password.

[kardianos]

You can't directly use the $HOME env var, go through user PKG. As indicated above, windows expects the name to be "_netrc". At least this is how git code review and windows git work.

[kardianos]

Yes, this line in vgo internal web2/web.go is wrong.
filepath.Join(os.Getenv("HOME"), ".netrc")

Use how code review does it:
https://github.com/golang/review/blob/0bdc7edde01a92e96255c6845b536d59706b9542/git-codereview/api.go#L130

[gopherbot]

Change https://golang.org/cl/103866 mentions this issue: x/vgo: netrc failing to load on Windows, possibly in wrong place