November 2024 - ruby-core - ml.ruby-lang.org

[ruby-core:119889] [Ruby master Feature#6648] Provide a standard API for retrieving all command-line flags passed to Ruby
by Eregon (Benoit Daloze) 12 Nov '24

12 Nov '24

Issue #6648 has been updated by Eregon (Benoit Daloze). nobu (Nobuyoshi Nakada) wrote in #note-43: > Saving a path string is not reliable. Why not? Are you thinking if the directory is removed? In that case there is no way to rerun the command faithfully, so an error like Errno::ENOENT is fine. ---------------------------------------- Feature #6648: Provide a standard API for retrieving all command-line flags passed to Ruby https://bugs.ruby-lang.org/issues/6648#change-110580 * Author: headius (Charles Nutter) * Status: Assigned * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- Currently there are no standard mechanisms to get the flags passed to the currently running Ruby implementation. The available mechanisms are not ideal: * Scanning globals and hoping they have not been tweaked to new settings * Using external wrappers to launch Ruby * ??? Inability to get the full set of command-line flags, including flags passed to the VM itself (and probably VM-specific) makes it impossible to launch subprocess Ruby instances with the same settings. A real world example of this is "((%bundle exec%))" when called with a command line that sets various flags, a la ((%jruby -Xsome.vm.setting --1.9 -S bundle exec%)). None of these flags can propagate to the subprocess, so odd behaviors result. The only option is to put the flags into an env var (((|JRUBY_OPTS|)) or ((|RUBYOPT|))) but this breaks the flow of calling a simple command line. JRuby provides mechanisms to get all its command line options, but they require calling Java APIs from Ruby's API set. Rubinius provides its own API for accessing comand-line options, but I do not know if it includes VM-level flags as well as standard Ruby flags. I know there is a (({RubyVM})) namespace in the 2.0 line. If that namespace is intended to be general-purpose for VM-level features, it would be a good host for this API. Something like... ``` class << RubyVM def vm_args; end # returns array of command line args *not* passed to the target script def script; end # returns the script being executed...though this overlaps with $0 def script_args; end # returns args passed to the script...though this overlaps with ARGV, but that is perhaps warranted since ARGV can be modified (i.e. you probably want the original args) end ``` -- https://bugs.ruby-lang.org/

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[ruby-core:119886] [Ruby master Feature#6648] Provide a standard API for retrieving all command-line flags passed to Ruby
by nobu (Nobuyoshi Nakada) 12 Nov '24

12 Nov '24

Issue #6648 has been updated by nobu (Nobuyoshi Nakada). Eregon (Benoit Daloze) wrote in #note-42: > @nobu True, it would also be helpful to have a way to capture the original CWD. > Then that example would work just fine with `ruby -C subdir -e 'exec(RbConfig.ruby, *Process.ruby_args, "-e", "p :OK", chdir: Process.original_working_directory)'` > (using the naming from https://bugs.ruby-lang.org/issues/6648#note-10 but with `Process`). How to "capture the original CWD"? Keeping a fd open is uselessly expensive in many case, I think. Saving a path string is not reliable. I think the method to run without `-C` options in the CWD is better. ---------------------------------------- Feature #6648: Provide a standard API for retrieving all command-line flags passed to Ruby https://bugs.ruby-lang.org/issues/6648#change-110576 * Author: headius (Charles Nutter) * Status: Assigned * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- Currently there are no standard mechanisms to get the flags passed to the currently running Ruby implementation. The available mechanisms are not ideal: * Scanning globals and hoping they have not been tweaked to new settings * Using external wrappers to launch Ruby * ??? Inability to get the full set of command-line flags, including flags passed to the VM itself (and probably VM-specific) makes it impossible to launch subprocess Ruby instances with the same settings. A real world example of this is "((%bundle exec%))" when called with a command line that sets various flags, a la ((%jruby -Xsome.vm.setting --1.9 -S bundle exec%)). None of these flags can propagate to the subprocess, so odd behaviors result. The only option is to put the flags into an env var (((|JRUBY_OPTS|)) or ((|RUBYOPT|))) but this breaks the flow of calling a simple command line. JRuby provides mechanisms to get all its command line options, but they require calling Java APIs from Ruby's API set. Rubinius provides its own API for accessing comand-line options, but I do not know if it includes VM-level flags as well as standard Ruby flags. I know there is a (({RubyVM})) namespace in the 2.0 line. If that namespace is intended to be general-purpose for VM-level features, it would be a good host for this API. Something like... ``` class << RubyVM def vm_args; end # returns array of command line args *not* passed to the target script def script; end # returns the script being executed...though this overlaps with $0 def script_args; end # returns args passed to the script...though this overlaps with ARGV, but that is perhaps warranted since ARGV can be modified (i.e. you probably want the original args) end ``` -- https://bugs.ruby-lang.org/

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[ruby-core:119506] [Ruby master Feature#20794] Expose information about the currently running GC module
by eightbitraptor (Matthew Valentine-House) 11 Nov '24

11 Nov '24

Issue #20794 has been reported by eightbitraptor (Matthew Valentine-House). ---------------------------------------- Feature #20794: Expose information about the currently running GC module https://bugs.ruby-lang.org/issues/20794 * Author: eightbitraptor (Matthew Valentine-House) * Status: Open ---------------------------------------- ## Summary [[Github PR #11872]](https://github.com/ruby/ruby/pull/11872) Currently it's not possible for the user to easily find out information about the currently running GC, and whether modular GC has been enabled. The linked PR provides a method for the user to query whether modular GC's are enabled, and whether one is active, as well as a Ruby method that exposes the currently active GC. ## Background Since Modular GC was introduced it's been possible to build Ruby with several different GC configurations: 1. Modular GC disabled. Existing GC is linked statically, and active - This is the default case 2. Modular GC enabled, but not loaded. Existing GC is linked statically and is active. 3. Modular GC enabled, and a GC implementation is loaded and overrides the static default GC. Currently there's not an accurate way of determining which of these states the current Ruby process is in. This makes writing tests that work accurately given different GC configurations complex. It also means that developers and admins running Ruby aren't able to get accurate information about their Ruby processes. ## Proposal This ticket proposes the following changes: * Add GC status to `RUBY_DESCRIPTION` so it's visible in the output of `ruby -v` * Add a method `GC.active_gc_name` that will return the name of the currently running GC as a String. ## Implementation The linked PR implements these proposals. #### No shared GC support This is the default case. Ruby statically links and uses the existing GC, with no means to override it. `RUBY_DESCRIPTION` is obviously unchanged ``` ❯ ruby -v ruby 3.4.0dev (2024-10-09T14:20:46Z mvh-active-gc-name 3cb4bd4d43) +PRISM [arm64-darwin24] ``` and `GC.active_gc_name` returns `nil` ``` ❯ ./ruby -e "p GC.active_gc_name" nil ``` #### Shared GC support enabled, Not loaded This is the case when Ruby has been configured with `--with-shared-gc=/path/to/gc` but no GC has been explicitly loaded using the `RUBY_GC_LIBRARY` environment `RUBY_DESCRIPTION` will contain `+MOD_GC` to indicate that shared GC support is built in. This is similar to how `+PRISM`, and `+YJIT` work. ``` ❯ ruby -v ruby 3.4.0dev (2024-10-09T14:38:38Z mvh-active-gc-name 3cb4bd4d43) +PRISM +MOD_GC [arm64-darwin24] ``` and `GC.active_gc_name` still returns `nil`. This is because the existing statically linked GC is in use, and has not been overridden. ``` ❯ ./ruby -e "p GC.active_gc_name" nil ``` #### Shared GC support enabled, and modular GC loaded This is the case when Ruby has been configured with `--with-shared-gc=/path/to/gc` **and** an alternative GC library has been explicitly loaded using the `RUBY_GC_LIBRARY` environment variable `RUBY_DESCRIPTION` will contain `+MOD_GC` to indicate that shared GC support is built in. This is similar to how `+PRISM`, and `+YJIT` work. In addition it will also contain a GC name, which is a human readable name that each concrete GC implementation needs to provide as part of its API. This is seen here as `+MOD_GC[mmtk]` - because in this case `librubygc.dylib` reports it's name as being `mmtk` ``` ❯ RUBY_GC_LIBRARY=librubygc.dylib ./ruby -v ruby 3.4.0dev (2024-10-09T14:38:38Z mvh-active-gc-name 3cb4bd4d43) +PRISM +MOD_GC[mmtk] [arm64-darwin24] ``` `GC.active_gc_name` returns the GC's name, as configured by the GC module (this will be identical to the reported name loaded into `RUBY_DESCRIPTION`). ``` ❯ RUBY_GC_LIBRARY=librubygc.dylib ./ruby -e "puts GC.active_gc_name" mmtk ``` ### Conclusion This should cover all states that the GC can now be in. Users can now query the state from the command line to see whether modular GC's are enabled and if so, what GC is active. From Ruby we can use `GC.active_gc_name` in conjunction with the pre-existing option `RbConfig::CONFIG['shared_gc_dir']` to find out this same information. This will now make it easier to run different Ruby processes with different GC builds, as well as make it easier for GC implementors to write tests that behave correctly in all these circumstances. -- https://bugs.ruby-lang.org/

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[ruby-core:119641] [Ruby master Bug#20853] Hash key retrieval after Process.warmup
by keelerm84 (Matthew Keeler) 10 Nov '24

10 Nov '24

Issue #20853 has been reported by keelerm84 (Matthew Keeler). ---------------------------------------- Bug #20853: Hash key retrieval after Process.warmup https://bugs.ruby-lang.org/issues/20853 * Author: keelerm84 (Matthew Keeler) * Status: Open * ruby -v: ruby 3.3.5 (2024-09-03 revision ef084cc8f4) [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- This was first reported as an issue against the [LaunchDarkly SDK](https://github.com/launchdarkly/ruby-server-sdk/issues/282) and [Sidekiq SDKs](https://github.com/sidekiq/sidekiq/issues/6279) as an issue in Ruby 3.3.1. I can still in Ruby 3.3.5. **Overview of behavior** The LaunchDarkly SDK maintains a hash of feature and segment information. This hash is indexed by 2 keys which are themselves hashes. They are defined as: ``` FEATURES = { namespace: "features", priority: 1, get_dependency_keys: lambda { |flag| (flag[:prerequisites] || []).map { |p| p[:key] } }, }.freeze SEGMENTS = { namespace: "segments", priority: 0, }.freeze ``` When running the attached script, we often see an error indicating that the flag is not found. If you comment out the `Process.warmup` line, this error will go away. The `require 'active_support/all'` directive is not strictly necessary. Including it causes the failure to more frequently occur, presumably due to the increase work in the warmup phase. **Hash key and access** When debugging the LaunchDarkly code, I noticed some odd behavior. Even though the hash seems populated, the FEATURES key could not index into it correctly. Below is a bit of code, modified from the SDK, to show how we are trying to interact with the hash. The puts are added to clarify the issue. ```ruby def get(kind, key) @lock.with_read_lock do @items.keys.each do |k| puts "##### Does #{kind[:namespace]} match the key #{k}? #{k == kind} #{k.eql?(kind)} #{k.hash == kind.hash}" end puts "###### Does @items include it? #{(a)items.include?(kind)}" coll = @items[kind] f = coll.nil? ? nil : coll[key.to_sym] (f.nil? || f[:deleted]) ? nil : f end end ``` *Running without Process.warmup* If we run the attached script without the `Process.warmup` call, we will see that the keys align with the FEATURES key we provided. Additionally, the hash does see that the key exists, resulting in an evaluation result of true at the end. That output follows. ```shell ##### Does features match the key {:namespace=>"segments", :priority=>0}? false false false ##### Does features match the key {:namespace=>"features", :priority=>1, :get_dependency_keys=>#<Proc:0x00007ee6174f9738 /home/mkeeler/code/launchdarkly/ruby-server-sdk.git/main/lib/ldclient-rb/in_memory_store.rb:17 (lambda)>}? true true true ###### Does @items include it? true true ``` *Running with Process.warmup* If you enable the `Process.warmup` option, and run the script a few times, you will see output similar to the following. Note that while the keys are `==`, `eql?`, and their `.hash` values are equal, the hash does not see that the FEATURES key exists. ```shell ##### Does features match the key {:namespace=>"segments", :priority=>0}? false false false ##### Does features match the key {:namespace=>"features", :priority=>1, :get_dependency_keys=>#<Proc:0x0000774f1cbfd730 /home/mkeeler/code/launchdarkly/ruby-server-sdk.git/main/lib/ldclient-rb/in_memory_store.rb:17 (lambda)>}? true true true ###### Does @items include it? false I, [2024-10-30T14:34:33.842145 #974568] INFO -- : [LDClient] Unknown feature flag "sample-feature". Returning default value false ``` **Workarounds** We have worked around this issue by replacing these keys with classes. You can refer to the [PR here](https://github.com/launchdarkly/ruby-server-sdk/pull/301/files) for those details. You can also resolve this by triggering a `rehash` on the hash after the `Process.warmup` has run. ---Files-------------------------------- main.rb (630 Bytes) Gemfile (96 Bytes) -- https://bugs.ruby-lang.org/

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[ruby-core:119868] [Ruby master Feature#17566] Tune thread QoS / efficiency on macOS
by shan (Shannon Skipper) 09 Nov '24

09 Nov '24

Issue #17566 has been updated by shan (Shannon Skipper). From Apple's perspective, it's our "obligation" as developers to make apps go "absolutely idle" on performance cores when "not responding to user input." From their docs, it seems they hope for us to use fine grained priority when we can. See https://developer.apple.com/news/?id=vk3m204o Apple silicon is so popular with programmers that I wonder if it's worth supporting QoS for the sake of developer tools written in Ruby? ---------------------------------------- Feature #17566: Tune thread QoS / efficiency on macOS https://bugs.ruby-lang.org/issues/17566#change-110559 * Author: mperham (Mike Perham) * Status: Open ---------------------------------------- Hi, new Apple M1 processors have "performance" and "efficiency" cores. Apple provides a QoS API so threads can tune which cores they should execute on. Some threads should be executed as high-priority, some should be treated as low-priority. This page shows the pthread APIs that Apple provides: https://developer.apple.com/library/archive/documentation/Performance/Conce… ``` pthread_set_qos_class_self_np(QOS_CLASS_BACKGROUND, 0) ``` I noticed Ruby already provides `Thread#priority=` which says `This is just hint for Ruby thread scheduler. It may be ignored on some platform`. Does this API work still or was it only active for Ruby 1.8's green threads? Should this API use the QoS APIs on macOS? -- https://bugs.ruby-lang.org/

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[ruby-core:119839] [Ruby master Bug#20881] Complex#** returns discontinuous results in Fixnum and Bignum exponents
by mame (Yusuke Endoh) 09 Nov '24

09 Nov '24

Issue #20881 has been reported by mame (Yusuke Endoh). ---------------------------------------- Bug #20881: Complex#** returns discontinuous results in Fixnum and Bignum exponents https://bugs.ruby-lang.org/issues/20881 * Author: mame (Yusuke Endoh) * Status: Open * Assignee: mrkn (Kenta Murata) * ruby -v: ruby 3.4.0dev (2024-10-18T02:35:00Z master 9a98b70a50) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- `Complex#**` performs the straightforward calculation when the exponent is Fixnum, but performs the computation in the polar coordinate system when the exponent is Bignum. Therefore, errors accumulate in the former case and not in the latter. ``` (Complex.polar(1, 1) ** 100000000000000).abs #=> 1.0033483420677842 (Complex.polar(1, 1) ** 1000000000000000).abs #=> 1.0339924646874608 (Complex.polar(1, 1) ** 10000000000000000).abs #=> 1.3969270854305682 (Complex.polar(1, 1) ** 100000000000000000).abs #=> 28.29680363011009 (Complex.polar(1, 1) ** 1000000000000000000).abs #=> 329134804659039.0 # ↑ Fixnum # ↓ Bignum (Complex.polar(1, 1) ** 10000000000000000000).abs #=> 1.0 (w/ warning: in a**b, b may be too big) (Complex.polar(1, 1) ** 100000000000000000000).abs #=> 0.9999999999999999 (w/ warning: in a**b, b may be too big) (Complex.polar(1, 1) ** 1000000000000000000000).abs #=> 1.0 (w/ warning: in a**b, b may be too big) ``` It may be good to always calculate them in the polar coordinate. I found this issue when addressing #20811. -- https://bugs.ruby-lang.org/

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[ruby-core:118976] [Ruby master Bug#20704] Windows: `-C` option does not work for multibyte path name
by nobu (Nobuyoshi Nakada) 08 Nov '24

08 Nov '24

Issue #20704 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #20704: Windows: `-C` option does not work for multibyte path name https://bugs.ruby-lang.org/issues/20704 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Related to [Bug #20699]. ``` C:> \Ruby33-x64\bin\ruby.exe -C xテスト_test -ep \Ruby33-x64\bin\ruby.exe: Can't chdir to xテスト_test (fatal) ``` -- https://bugs.ruby-lang.org/

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[ruby-core:119495] [Ruby master Feature#20792] String#forcible_encoding?
by kddnewton (Kevin Newton) 08 Nov '24

08 Nov '24

Issue #20792 has been reported by kddnewton (Kevin Newton). ---------------------------------------- Feature #20792: String#forcible_encoding? https://bugs.ruby-lang.org/issues/20792 * Author: kddnewton (Kevin Newton) * Status: Open ---------------------------------------- I would like to add a method to String called `forcible_encoding?(encoding)`. This would return true or false depending on whether the receiver can be forced into the given encoding without breaking the string. It would effectively be an alias for: ```ruby def forcible_encoding?(enc) original = encoding result = force_encoding(enc).valid_encoding? force_encoding(original) result end ``` I would like this method because there are extremely rare but possible circumstances where source files are marked as binary but contain UTF-8-encoded characters. In that case I would like to check if it's possible to cleanly force UTF-8 before actually doing it. The code I'm trying to replace is here: https://github.com/ruby/prism/blob/d6e9b8de36b4d18debfe36e4545116539964ceeb…. The pull request for the code is here: https://github.com/ruby/ruby/pull/11851. -- https://bugs.ruby-lang.org/

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[ruby-core:119726] [Ruby master Feature#20864] Support `error:` keyword to `Kernel#warn`
by ioquatix (Samuel Williams) 08 Nov '24

08 Nov '24

Issue #20864 has been reported by ioquatix (Samuel Williams). ---------------------------------------- Feature #20864: Support `error:` keyword to `Kernel#warn` https://bugs.ruby-lang.org/issues/20864 * Author: ioquatix (Samuel Williams) * Status: Open ---------------------------------------- `Kernel#warn` is extremely useful. It is possible to include some details about the current caller using `uplevel` for the current call stack. But it is not possible to include details about errors. I'd like to propose another extension to log errors. ```ruby begin # some work rescue => error warn "An error occurred!", error: error end ``` Such a feature would allow us to log errors using a standard interface. I don't have an opinion about the implementation, but I wanted to get feedback on the interface. -- https://bugs.ruby-lang.org/

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[ruby-core:119602] [Ruby master Feature#20811] `warning: in a**b, b may be too big` is really helpful?
by mame (Yusuke Endoh) 08 Nov '24

08 Nov '24

Issue #20811 has been reported by mame (Yusuke Endoh). ---------------------------------------- Feature #20811: `warning: in a**b, b may be too big` is really helpful? https://bugs.ruby-lang.org/issues/20811 * Author: mame (Yusuke Endoh) * Status: Open ---------------------------------------- I tried to calculate the largest prime number recently discovered. However, it did not work. I was a bit disappointed. ``` $ ruby -e 'p 2**136279841-1' -e:1: warning: in a**b, b may be too big Infinity ``` I know this is not a realistic case, but I checked my past chat logs and found a record of the same thing six years ago and the same disappointment. ``` $ ruby -e 'p 2**77232917-1' -e:1: warning: in a**b, b may be too big Infinity ``` So I would like to ask, has anyone experienced that this behavior has actually been helpful? I think that this limit is to prevent a program from unintentionally spending too much time and memory trying to compute a power that is too large. However, is it helpful to return Infinity in such a situation? I think raising an exception would be safer, if this limit is really needed. Also, is this limit appropriate? On my machine, `2 ** 32537661` is calculated normally and `2 ** 32537662` returns Infinity. This calculation took about 100 ms and 400 kB. I think this is short enough for a single computation time. Incidentally, `2 ** 32537661` in decimal notation is 9,794,814 digits, which may be too loose a limit considering the display. Note that this limit only applies when calculating the power directly. `(2 ** 32537661) * 2` returns an Integer, not Infinity. Even `1 << 32537662` gives an Integer. From the above, I suspect that this limit is not particularly useful and only spoils the fun of mathematics. What do you think? -- https://bugs.ruby-lang.org/

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