However, I also feel that Ruby sometimes seems too focused on being backwards compatible, to a point where it risk hurting the ecosystem. I think this thread is a good example, because it seems like such a small and benign change, yet it's taken several years and lots of back and forth, and in the end the proposed change wasn't even applied(!?).

IRIs are mapped to URIs to retain backwards-compatibility with systems that do not support the new format.

Agree, but we're stuck with API compatibility for a good while.

Note that this is a breaking API change in the libraries (more information in the README.md). It does not affect the backwards compatibility of the protocol itself.

Will my code break on Ruby 2.7? A short answer is “maybe not”. The changes in Ruby 2.7 are designed as a migration path towards 3.0. While in principle, Ruby 2.7 only warns against behaviors that will change in Ruby 3, it includes some incompatible changes we consider to be minor. See the “Other minor changes” section for details. Except for the warnings and minor changes, Ruby 2.7 attempts to keep the compatibility with Ruby 2.6. So, your code will probably work on Ruby 2.7, though it may emit warnings. And by running it on Ruby 2.7, you can check if your code is ready for Ruby 3.0.

I'm not very familiar with this feature. Do you know what version of Rails is required for this code to work? Is it Rails 6.0+? We run the test suite via Travis CI for many versions of Rails so I am concerned that this will cause test failures on older versions. Can we write the tests so that they gracefully exclude the CSP stuff on older versions where CSP is not supported?

{a: 1, b: 2, c: 3, d: 4} => {a:, b:, **rest} # a == 1, b == 2, rest == {:c=>3, :d=>4}

{a, b, ...rest} = {a: 1, b: 2, c: 3, d: 4}

The problem with using a newer distro is that it upgrades glibc, which is bad for compatibility with older distros.

The backwards compatible implementation of jsx(...), we would still support key passed as props. We'd just pull it off props and issue a warning that this pattern is deprecated. The upgrade path is to just pass it to JSX separately if you need it.

It's easy to persist the entire application state in a way that is backwards-compatible, so persisted states can survive application changes.

It does, however, provide the --porcelain option, which causes the output of git status --porcelain to be formatted in an easy-to-parse format for scripts, and will remain stable across Git versions and regardless of user configuration.

Downgrade the API version used at run time by exporting the DOCKER_API_VERSION=1.21 to environment variable on the client side.

In the future, these attributes may expand without the API being versioned. The current attributes are: