`bundle platform` doesn't indicate that BUNDLE_FORCE_RUBY_PLATFORM is in effect, and neither does anything else

Describe the problem as clearly as you can

We recently had a difficult to diagnose problem.

The summary of the issue is this:

• Running on an arm based laptop
• A repo had .bundle/config with BUNDLE_FORCE_RUBY_PLATFORM set
• A gem was added to the repo which had a ruby-platform version, but the ruby-platform version had an amd64 binary in it
• Bundler was installing the incorrect version of the gem

Did you try upgrading rubygems & bundler?

Yep

Which command did you run?

In diagnosing the problem, we ran bundle platform and ruby -e "puts Gem::Platform.local", but they both emitted the expected arm64, even though BUNDLE_FORCE_RUBY_PLATFORM was set to true.

What were you expecting to happen?

The situation is incredibly obscure, but I think looking back to it I would have expected bundle platform to:

• warn about the config override
• or say that it would have installed the ruby platform as configured

What actually happened?

> bundle platform
Your platform is: arm64-darwin-24

Your app has gems that work on these platforms:
* aarch64-linux
* arm-linux
* arm64-darwin
* ruby
* x86-linux
* x86_64-darwin
* x86_64-linux

Your Gemfile specifies a Ruby version requirement:
* ruby 3.3.0

Your current platform satisfies the Ruby version requirement.

Start at the bundle platform command and trace how BUNDLE_FORCE_RUBY_PLATFORM is read alongside Gem::Platform.local. Compare the platform it reports with the platform used for installation, then define how the override should be surfaced; done means this arm64/amd64 scenario is no longer misleading.