NEWS for Ruby 4.1.0

This document is a list of user-visible feature changes since the 4.0.0 release, except for bug fixes.

Note that each entry is kept to a minimum, see links for details.

Language changes

• Module#clone and Module#dup no longer rewrite the lexical scope of copied methods. Constants and class variables resolve through the original class, consistent with inheritance and mixins. [Feature #21981]

Core classes updates

Note: We’re only listing outstanding class updates.

• C API

  • RB_NOGVL_PENDING_INTR_FAIL is added as a flag for rb_nogvl. rb_nogvl does not enter the blocking region (and does not call the given function), returning 0, if the current thread has pending interrupts, including interrupts masked by Thread.handle_interrupt. As with the existing skip path, errno is 0 because the function was never called.

• Array

  • Array#pack accepts new formats R and r for unsigned and signed LEB128 encoded integers. [Feature #21785]

  • Array#pack accepts new formats x! and @! to align the current offset to a byte boundary or to the ABI alignment of another directive. [Feature #22185]

• ENV

  • ENV.fetch_values is added. It returns an array of values for the given names, raising KeyError for missing names unless a block is given. [Feature #21781]

• Integer

  • Integer#bit_count is added. It returns the number of 1 bits in the binary representation of a non-negative integer (its population count). [Feature #20163]

• Kernel

  • Kernel#autoload_relative and Module#autoload_relative are added. These methods work like autoload, but resolve the file path relative to the file where the method is called, similar to require_relative. This makes it easier to autoload constants from files in the same directory without hardcoding absolute paths or manipulating $LOAD_PATH. [Feature #15330]

• MatchData

  • MatchData#integer_at is added. It converts the matched substring to integer and return the result. [Feature #21932]

• ObjectSpace

  • ObjectSpace._id2ref was removed. [Feature #22135]

• Proc

  • Proc#refined is added. It returns a new Proc that behaves like the receiver but with the refinements activated by the given modules in effect inside its body, without affecting the original Proc. [Feature #22097]

• Range

  • Range#clamp is added. It returns a new Range instance whose begin and end values are clamped to the given bounds. [Feature #22175]

• Regexp

  • All instances of Regexp are now frozen, not just literals. Subclasses of Regexp are not frozen for compatibility. [Feature #8948]

• Set

  • A deprecated behavior, Set#to_set, Range#to_set, and Enumerable#to_set accepting arguments, was removed. [Feature #21390]

• String

  • String#unpack and String#unpack1 accept new formats R and r for unsigned and signed LEB128 encoded integers. [Feature #21785]

  • String#unpack and String#unpack1 accept a new format ^ that returns the current offset. Useful when combined with variable width formats like LEB128. [Feature #21796]

  • String#unpack and String#unpack1 accept new formats x! and @! to align the current offset to a byte boundary or to the ABI alignment of another directive. [Feature #22185]

• Symbol

  • Symbol#to_s now returns a frozen string. [Feature #22137]

Stdlib updates

• Psych

  • An experimental libfyaml backend has been added. It is only enabled when psych is built with --enable-libfyaml, and the default libyaml backend remains unchanged otherwise. It is not supported on Windows. [GH-psych #805]

The following bundled gems are added.

We only list stdlib changes that are notable feature changes.

Other changes are listed in the following sections. We also listed release history from the previous bundled version that is Ruby 3.4.0 if it has GitHub releases.

The following bundled gems are promoted from default gems.

• tsort 0.2.0

• win32-registry 0.1.2

The following bundled gems are removed.

• net-ftp 0.3.9

• net-pop 0.1.2

They are still available on rubygems.org and can be installed with gem install. [Feature #21835]

The following default gem is added.

The following default gems are updated.

• RubyGems 4.1.0.dev

• 4.0.3 to v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8, v4.0.9, v4.0.10, v4.0.11, v4.0.12, v4.0.13, v4.0.14, v4.0.15, v4.0.16, v4.0.17, v4.0.18

• bundler 4.1.0.dev

• 4.0.3 to v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8, v4.0.9, v4.0.10, v4.0.11, v4.0.12, v4.0.13, v4.0.14, v4.0.15, v4.0.16, v4.0.17

• erb 6.0.7

• 6.0.1 to v6.0.1.1, v6.0.2, v6.0.3, v6.0.4, v6.0.5, v6.0.6, v6.0.7

• error_highlight 0.7.2

• ipaddr 1.2.9

• 1.2.8 to v1.2.9

• json 2.21.2

• 2.18.0 to v2.18.1, v2.19.0, v2.19.1, v2.19.2, v2.19.3, v2.19.4, v2.19.5, v2.19.6, v2.19.7, v2.19.8, v2.19.9, v2.20.0, v2.21.0, v2.21.2

• openssl 4.0.2

• 4.0.0 to v4.0.1, v4.0.2

• pp 0.6.4

• 0.6.3 to v0.6.4

• prism 1.9.0

• 1.7.0 to v1.8.0, v1.8.1, v1.9.0

• psych 5.4.0

• 5.3.1 to v5.4.0

• resolv 0.7.1

• 0.7.0 to v0.7.1

• stringio 3.2.1.dev

• strscan 3.1.9.dev

• 3.1.6 to v3.1.7, v3.1.8

• syntax_suggest 3.0.0

• timeout 0.6.1

• 0.6.0 to v0.6.1

• zlib 3.2.3

• 3.2.2 to v3.2.3

The following bundled gems are updated.

• minitest 6.0.6

• rake 13.4.2

• 13.3.1 to v13.4.0, v13.4.1, v13.4.2

• test-unit 3.7.8

• 3.7.5 to 3.7.6, 3.7.7, 3.7.8

• rss 0.3.3

• 0.3.2 to 0.3.3

• net-imap 0.6.6

• 0.6.2 to v0.6.3, v0.6.4, v0.6.4.1, v0.6.5, v0.6.6

• rbs 4.0.3

• 3.10.0 to v3.10.1, v3.10.2, v3.10.3, v3.10.4, v4.0.0.dev.1, v4.0.0.dev.2, v4.0.0.dev.3, v4.0.0.dev.4, v4.0.0.dev.5, v4.0.0, v4.0.1.dev.1, v4.0.1.dev.2, v4.0.1, v4.0.2, v4.0.3

• typeprof 0.32.0

• mutex_m 0.3.0

• bigdecimal 4.1.2

• 4.0.1 to v4.1.0, v4.1.1, v4.1.2

• resolv-replace 0.2.0

• 0.1.1 to v0.2.0

• nkf 0.3.0

• 0.2.0 to v0.3.0

• syslog 0.4.0

• 0.3.0 to v0.4.0

• csv 3.3.6

• 3.3.5 to v3.3.6

• repl_type_completor 0.1.16

• 0.1.12 to v0.1.13, v0.1.14, v0.1.15, v0.1.16

• pstore 0.2.1

• 0.2.0 to v0.2.1

• rdoc 8.0.0

• 7.0.3 to v7.0.4, v7.1.0, v7.2.0, v8.0.0

• win32ole 1.9.3

• 1.9.2 to v1.9.3

• irb 1.18.0

• 1.16.0 to v1.17.0, v1.18.0

RubyGems and Bundler

Ruby 4.0 bundled RubyGems and Bundler version 4. see the following links for details.

Supported platforms

• Support code for the following platforms has been removed. Note that all of them reached end of life many years ago and Ruby has long been unbuildable on them.

  • Interix (Windows Services for UNIX)

  • SunOS 4 (Solaris, i.e. SunOS 5, is unaffected)

  • BSD/OS (BSDi)

Compatibility issues

• Kernel#at_exit and END {} now raise Ractor::IsolationError when called in a non-main Ractor. Previously the registered handler ran in the main Ractor at process exit, which was confusing. [Feature #22139]

• Ractor.make_shareable now raises Ractor::Error for an IO object, and Ractor.shareable? returns false for it. A frozen IO used to be shareable, but almost all of its methods raise FrozenError and it can still refer to unshareable objects through the members of rb_io_t.

Stdlib compatibility issues

C API updates

Embedded TypedData

• The RUBY_TYPED_EMBEDDABLE flag is now public and documented and can be used by C extensions. It allows allocating C structs directly into Ruby object slots, which reduces pointer chasing, and in some case memory usage. See the C extension documentation for details. [Feature #21853]

• Added new C23 inspired allocator functions, that takes the previous memory size. This allow the Ruby GC to better keep track of memory usage, improving its heuristics. It also improves the performance of system allocators that support C23 free_sized.

However, it is important to note that passing an incorrect size to these function is undefined behavior and may result in crashes or memory leaks.

• ruby_xfree_sized(void *ptr, size_t size)

• ruby_xrealloc_sized(void *ptr, size_t newsiz, size_t oldsiz)

• ruby_xrealloc2_sized(void *ptr, size_t newelems, size_t newsiz, size_t oldelems)

[Feature #21861]

Removed APIs

The following APIs, which have been deprecated for many years, are removed. [Feature #21768]

• old postponed job functions,

• untyped data object type/functions,

• old APIs to allocate a data object,

• taintedness/trustedness enums/macros,

• rb_gc_force_recycle function,

• rb_iterate function,

• and some functions and constants for internal use.

Implementation improvements

• The default garbage collector has been switched from a freelist allocator to a bump pointer allocator. [PR #17201]

• The error_highlight, did_you_mean, and syntax_suggest gems are now loaded lazily on the first error display instead of at interpreter boot, which reduces startup time. Process.warmup loads them eagerly so that pre-forking servers keep their code in copy-on-write shared memory. [Feature #21951]

Ractor

A lot of work has gone into making Ractors more stable, performant, and usable. These improvements bring Ractor implementation closer to leaving experimental status.

JIT