`_maybe_wrap_launcher_for_windows` selects wrapper based on target platform

[malt3]

_maybe_wrap_launcher_for_windows selects wrapper based on target platform.

By using ctx.target_platform_has_constraint(ctx.attr._windows_constraint[platform_common.ConstraintValueInfo]), the bat wrapper is added when targeting windows and not when executing actions on Windows.
This breaks in two cases:

• When cross compiling on Windows, the wrapper is not added (since the target platform is linux)
• When targeting windows on Linux (with transitions), the bat wrapper is added and fails

I feel like this should use a different mechanism to select the correct wrapper based on the execution platform.

EDIT: I'm not sure if I understand all of the nuance here but I think we could either add an attribute to rules:

_is_windows = select({
        "@bazel_tools//src/conditions:host_windows": True,
        "//conditions:default": False,
}),

... or do the wrapping as part of a toolchain. What do you think?

[alexeagle]

Ugh, yeah. This is an old thread, I recall having misgivings about it in earlier PRs.

bazel-contrib/bazel-lib#95
-> aspect-build/rules_js#986

FYI @gregmagolan

[thesayyn]

@alexeagle i created bazel-contrib/bazel-lib#702 which ought to solve this.