Ruby Issue Tracking System

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08:39 AM Ruby Revision 03d8b94e (git): Fix flaky TCPSocket#local_address implicit-hostname spec

The "using an implicit hostname" example connects with TCPSocket.new(nil,
port) to a server bound to the IPv4 loopback, then asserts that
local_address.ip_address equals @host ("127.0.0.1"). This is flaky.
A nil hostname resolves to the... ko1 (Koichi Sasada)

02:01 AM Ruby Feature #22132: Scala-like for comprehensions

BTW Elixir has `into: obj` https://elixir.hexdocs.pm/comprehensions.html#the-into-option so if we introduce `Hash#<<`, we can construct a hash with this syntax.
```ruby
for k in %w(foo bar),
v in 1..3 then
["#{k}_#{v}", v]
end int... ko1 (Koichi Sasada)

01:53 AM Ruby Feature #22132: Scala-like for comprehensions

1. It seems simpler to use `each` with accumulation like that:
```ruby
def foo(n, v)
for i in 0...n,
j in 0...n when i + j == v then
[i, j]
end
end
#=>
def foo(n, v)
_a = []
i = j = nil
(0...n).each do
i = it
... ko1 (Koichi Sasada)

07/01/2026

08:46 PM Ruby Revision cd54d0f9 (git): Fix flaky TestGc#test_stat_single by disabling GC

test_stat_single fails intermittently:
1) Failure:
TestGc#test_stat_single [test/ruby/test_gc.rb:198]:
<12> expected but was
<13>.
The test reads the full GC.stat hash and then GC.stat(:count) separately
and asserts they are eq... ko1 (Koichi Sasada)

08:19 PM Ruby Revision 8e6fd8fe (git): fix control flow

`do { ...; continue; } while(0)` doesn't retry the loop body.
pointed out by Coverity Scan and mame. ko1 (Koichi Sasada)

06:53 PM Ruby Feature #22139: Prohibit `END{}`/`Kernel#at_exit` in non-main Ractor

https://github.com/ruby/ruby/pull/17614 ko1 (Koichi Sasada)

06:22 PM Ruby Feature #22139 (Open): Prohibit `END{}`/`Kernel#at_exit` in non-main Ractor

Let's prohibit `END{}`/`Kernel#at_exit` on non-main Ractor.
The current behavior is strange:
```ruby
Ractor.new{
at_exit{ p [self, Ractor.current] }
}
sleep 1
#=> [#<Ractor:#2 t.rb:2 terminated>, #<Ractor:#1 running>]
`... ko1 (Koichi Sasada)

06/29/2026

06:21 AM Ruby Feature #22130: Add a new YARV instruction for a `String.new` fast path

How about to introduce `String.new_buffer(capacity)` or some other name if it is important for the performance? ko1 (Koichi Sasada)

02:03 AM Ruby Feature #22132: Scala-like for comprehensions

also this proposal contains extension like `for iter1, iter2 do ... end`? ko1 (Koichi Sasada)

02:00 AM Ruby Feature #22132: Scala-like for comprehensions

just curious: `for ... then` for single iterator will makes `map` behavior like that?
```ruby
for a in ary do
a
end
# ary.each{it}
for a in ary then
a
end
# ary.map{it}
```
ko1 (Koichi Sasada)