F38 proposal: Ruby 3.2 (System-Wide Change proposal)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/Ruby_3.2

This document represents a proposed Change. As part of the Changes
process, proposals are publicly announced in order to receive
community feedback. This proposal will only be implemented if approved
by the Fedora Engineering Steering Committee.

== Summary ==
Ruby 3.2 is the latest stable version of Ruby. Many new features and
improvements are included for the increasingly diverse and expanding
demands for Ruby. With this major update from Ruby 3.1 in Fedora 37 to
Ruby 3.2 in Fedora 38, Fedora becomes the superior Ruby development
platform.

== Owner ==
* Name: [[User:vondruch| Vít Ondruch]]
* Email: vondruch(a)redhat.com


== Detailed Description ==
Ruby 3.1 is upstream's new major release of Ruby. Many new features
and improvements are included.

=== WASI based WebAssembly support ===

This is an initial port of WASI based WebAssembly support. This
enables a CRuby binary to be available on Web browser, Serverless Edge
environment, and other WebAssembly/WASI embedders. Currently this port
passes basic and bootstrap test suites not using Thread API.

=== Regexp timeout ===

A timeout feature for Regexp matching is introduced.

It is known that Regexp matching may take unexpectedly long. If your
code attempts to match an possibly inefficient Regexp against an
untrusted input, an attacker may exploit it for efficient Denial of
Service (so-called Regular expression DoS, or ReDoS).

The risk of DoS can be prevented or significantly mitigated by
configuring `Regexp.timeout` according to the requirements of your
Ruby application. Please try it out in your application and welcome
your feedback.

=== Other Notable New Features ===

* Language
** Anonymous rest and keyword rest arguments can now be passed as
arguments, instead of just used in method parameters.
** A proc that accepts a single positional argument and keywords will
no longer autosplat.
** Constant assignment evaluation order for constants set on explicit
objects has been made consistent with single attribute assignment
evaluation order.
** Find pattern is no longer experimental.
** Methods taking a rest parameter and wishing to delegate keyword
arguments through `foo(*args)` must now be marked with
`ruby2_keywords`
* Performance improvements
** YJIT
*** Support arm64 / aarch64 on UNIX platforms.
*** Building YJIT requires Rust 1.58.1+.

=== Other notable changes since 3.1 ===

* Hash
** Hash#shift now always returns nil if the hash is empty, instead of
returning the default value or calling the default proc.
* MatchData
** MatchData#byteoffset has been added.
* Module
** Module.used_refinements has been added.
** Module#refinements has been added.
** Module#const_added has been added.
* Proc
** Proc#dup returns an instance of subclass.
** Proc#parameters now accepts lambda keyword.
* Refinement
** Refinement#refined_class has been added.
* Set
** Set is now available as a builtin class without the need for
`require "set"`. It is currently autoloaded via the `Set` constant or
a call to `Enumerable#to_set`.
* String
** String#byteindex and String#byterindex have been added.
** Update Unicode to Version 14.0.0 and Emoji Version 14.0. (also
applies to Regexp)
** String#bytesplice has been added.
* Struct
** A Struct class can also be initialized with keyword arguments
without `keyword_init: true` on `Struct.new`

=== Compatibility issues ===

* Removed constants
** `Fixnum` and `Bignum`
** `Random::DEFAULT`
** `Struct::Group`
** `Struct::Passwd`
* Removed methods
** `Dir.exists?`
** `File.exists?`
** `Kernel#=~`
** `Kernel#taint`, `Kernel#untaint`, `Kernel#tainted?`
** `Kernel#trust`, `Kernel#untrust`, `Kernel#untrusted?`

=== C API updates ===

* Removed C APIs
** `rb_cData` variable.
** "taintedness" and "trustedness" functions.


== Benefit to Fedora ==
With a latest release, Ruby language is supporting the newest language
features, which enables even faster and easier development of Ruby
applications.

== Scope ==
* Proposal owners:
** Finish packaging of Ruby 3.2. Current changes available in PR
https://src.fedoraproject.org/rpms/ruby/pull-request/134
** Rebuilding of Ruby packages providing native extensions (i.e.
packages which depends on libruby).

* Other developers:
** Rebuild of packages with binary extensions (i.e. packages which
depends on libruby) will be handled automatically, but some packages
might need fixes/updates to support Ruby 3.2 properly.

* Release engineering: [https://pagure.io/releng/issues/11115 #11115]
** The packages are going to be rebuild in side-tag, but that does not
need releng involvement nowadays.

* Policies and guidelines: N/A (not needed for this Change)
* Trademark approval: N/A (not needed for this Change)
* Alignment with Objectives:


== Upgrade/compatibility impact ==
* User specific Ruby binary extensions need to be rebuild.
* Ruby packages/application dependencies might need to be adjusted if
newly bundled gems are used.

== How To Test ==
* No special hardware is needed.
* To test, install Ruby 3.2. The test builds are published in PR or on
Ruby-SIG ML
* Try to locally rebuild your packages using Ruby 3.2.
* Use the packages with your applications previously written in Ruby.
* If something doesn't work as it should, let us know.

== User Experience ==
The Ruby programs/scripts should behave as they were used to.

== Dependencies ==
<!-- What other packages (RPMs) depend on this package?  Are there
changes outside the developers' control on which completion of this
change depends?  In other words, completion of another change owned by
someone else and might cause you to not be able to finish on time or
that you would need to coordinate?  Other upstream projects like the
kernel (if this is not a kernel change)? -->

<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<pre>
$ dnf repoquery --disablerepo=* --enablerepo=rawhide
--enablerepo=rawhide-source --arch=src --whatrequires 'ruby-devel' |
sort | uniq | wc -l
130
</pre>

== Contingency Plan ==
* Contingency mechanism: We would like to get a special buildroot tag
to be able to rebuild necessary the packages with Ruby 3.2. If
anything goes wrong, the tag could be easily dropped and previous
version of Ruby 3.1 and its dependencies stays intact. The tag would
be merged into F38 after everything is rebuild
* Contingency deadline: Mass Rebuild
* Blocks release? No


== Documentation ==
* [http://www.ruby-doc.org/ Help and documentation for the Ruby
programming language]
* [https://github.com/ruby/ruby/blob/master/NEWS.md Ruby 3.2.0 NEWS]
* [https://www.ruby-lang.org/en/news/2022/09/09/ruby-3-2-0-preview2-released/
Ruby 3.2 Preview 2 release announcement]

== Release Notes ==
* The Ruby 3.2 bumps soname, therefore Ruby packages, which use binary
extensions, should be rebuilt. Nevertheless, since upstream paid great
attention to source compatibility, no changes to your code are needed.

https://github.com/ruby/ruby/blob/master/NEWS.md


-- 
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis