Description of the problem / feature request:

When overriding the copts and linkopts build configuration with None values in a transition, Bazel crashes with a NullPointerException.

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

def _my_transition_impl(settings, attr):
    return {
        "//command_line_

Currently such a request would return an HTTP 500:

curl -H "Authorization: Bearer <valid token>" "http://localhost:7575/v1/packages/not-a-real-package-id"

I believe this is unexpected and an HTTP 404 would be more appropriate, which would mean (specification):

10.4.5 404 Not Found

The server has not found anythi

This might be faster:
git clone /path/to/base/head/startup-os

We could also probably do:
git clone file:///path/to/base/head/startup-os --depth=1

See if we can replace sanitize_string_for_usage with code from skylib (existing or to contribute back).
Motivation for generalization- Recurring pattern of sanitizing inputs

Since bazelbuild/rules_rust#612 we test more stuff on Windows, we don't test everything though. //test/rustfmt is currently disabled in .bazelci/presubmit.yml.

Feel free to comment on this issue if you want to know more or you want to give it a shot. We are happy to talk or help :)

How to fix when you don't have a Windows machine:

1. delete the line with ` - "-//t