Make %USERPROFILE%\_netrc the default location for the netrc file on Windows

[plule-ansys]

Description of the problem / feature request:

Bazel has a default "netrc" file location under Linux and Mac OS, but not under Windows. This is identified as "TODO" in http.bzl

Feature requests: what underlying problem are you trying to solve with this feature?

Not having a default location for the netrc file on Windows makes it hard to use, especially as http_archive requires an absolute path ( #10689 ). The only supported way is to use a hard-coded path such as "C:/netrc".

Proposed Solution

Use "%USERPROFILE%/_netrc" as a default location. While GNU does not define any location for Windows, this location is de facto the one being used. This location is used by:

• curl/libcurl
• By extension any software using libcurl, including git credential manager
• Go langage
• Heroku Ruby Library

What operating system are you running Bazel on?

Windows 10

What's the output of bazel info release?

release 2.1.0