Thread.new do
  Fiber.new do
    # Consume more than the default stack:
    i = 0
    while true
      puts i: i
      Fiber.consume_stack(1024*i)
      i += 1
    end
  end.resume
end.join

samuel@Sakura ~/D/i/ruby-darwin-check_overflow-fix (darwin-check_overflow-fix) [2]> make runruby
compiling thread.c
linking miniruby
ln -sf ../../rbconfig.rb .ext/arm64-darwin24/rbconfig.rb
builtin_binary.inc updated
1092d1a331c3be9c2b03728f93d002c1a71e7a20599d18ac60891c3d2023937e  builtin_binary.inc
compiling builtin.c
linking static-library libruby.3.5-static.a
linking ruby
ld: warning: ignoring duplicate libraries: '-ldl', '-lobjc', '-lpthread'
RUBY_ON_BUG='gdb -x ./.gdbinit -p' ./miniruby -I./lib -I. -I.ext/common  ./tool/runruby.rb --extout=.ext  -- --disable-gems  ./test.rb 
{i: 0}
{i: 1}
{i: 2}
{i: 3}
{i: 4}
{i: 5}
{i: 6}
{i: 7}
{i: 8}
{i: 9}
{i: 10}
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{i: 41}
{i: 42}
{i: 43}
{i: 44}
{i: 45}
{i: 46}
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{i: 49}
{i: 50}
{i: 51}
{i: 52}
{i: 53}
{i: 54}
{i: 55}
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{i: 58}
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{i: 79}
{i: 80}
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{i: 83}
{i: 84}
{i: 85}
{i: 86}
{i: 87}
{i: 88}
{i: 89}
{i: 90}
{i: 91}
{i: 92}
{i: 93}
{i: 94}
{i: 95}
{i: 96}
{i: 97}
{i: 98}
{i: 99}
{i: 100}
{i: 101}
{i: 102}
{i: 103}
{i: 104}
{i: 105}
{i: 106}
{i: 107}
{i: 108}
{i: 109}
{i: 110}
{i: 111}
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{i: 113}
{i: 114}
{i: 115}
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{i: 117}
{i: 118}
{i: 119}
{i: 120}
{i: 121}
{i: 122}
{i: 123}
{i: 124}
{i: 125}
{i: 126}
{i: 127}
{i: 128}
{i: 129}
{i: 130}
{i: 131}
{i: 132}
{i: 133}
{i: 134}
{i: 135}
{i: 136}
{i: 137}
{i: 138}
{i: 139}
{i: 140}
{i: 141}
{i: 142}
{i: 143}
./test.rb:7: [BUG] Bus Error at 0x000000011a93bde0
ruby 3.5.0dev (2025-04-10T23:51:15Z darwin-check_overf.. 1f6edd3a8c) +PRISM [arm64-darwin24]

-- Crash Report log information --------------------------------------------
   See Crash Report log file in one of the following locations:             
     * ~/Library/Logs/DiagnosticReports                                     
     * /Library/Logs/DiagnosticReports                                      
   for more details.                                                        
Don't forget to include the above Crash Report log file in bug reports.     

sh: gdb: command not found
-- Control frame information -----------------------------------------------
c:0003 p:---- s:0012 e:000011 CFUNC  :consume_stack
c:0002 p:0023 s:0007 e:000006 BLOCK  ./test.rb:7 [FINISH]
c:0001 p:---- s:0003 e:000002 DUMMY  [FINISH]

-- Ruby level backtrace information ----------------------------------------
./test.rb:7:in 'block (2 levels) in <main>'
./test.rb:7:in 'consume_stack'

-- Threading information ---------------------------------------------------
Total ractor count: 1
Ruby thread count for this ractor: 2

-- Machine register context ------------------------------------------------
  x0: 0x0000000100bfac88  x1: 0x0000000000023c00  x2: 0x000000011a960040
  x3: 0x0000000100536ee0  x4: 0x000000011a960040  x5: 0x000000011a960038
  x6: 0x7d333431203a697b  x7: 0x0000000000000021 x18: 0x0000000000000000
 x19: 0x00000001467043e0 x20: 0x0000000100c15178 x21: 0x0000000100bfac88
 x22: 0x000000011a97ff90 x23: 0x0000000000000001 x24: 0x000000011a960040
 x25: 0x000000011a960038 x26: 0x0000000055550083 x27: 0x0000000146647010
 x28: 0x0000000000000000  lr: 0x0000000100536f28  fp: 0x000000011a95fa00
  sp: 0x000000011a95f9e0

-- C level backtrace information -------------------------------------------
SEGV received in BUS handler
make: *** [runruby] Abort trap: 6

samuel@Sakura ~/D/i/ruby-darwin-check_overflow-fix (darwin-check_overflow-fix) [2]> make runruby
compiling thread.c
linking miniruby
ln -sf ../../rbconfig.rb .ext/arm64-darwin24/rbconfig.rb
builtin_binary.inc updated
1092d1a331c3be9c2b03728f93d002c1a71e7a20599d18ac60891c3d2023937e  builtin_binary.inc
compiling builtin.c
linking static-library libruby.3.5-static.a
linking ruby
ld: warning: ignoring duplicate libraries: '-ldl', '-lobjc', '-lpthread'
RUBY_ON_BUG='gdb -x ./.gdbinit -p' ./miniruby -I./lib -I. -I.ext/common  ./tool/runruby.rb --extout=.ext  -- --disable-gems  ./test.rb 
{i: 0}
{i: 1}
{i: 2}
{i: 3}
{i: 4}
{i: 5}
{i: 6}
{i: 7}
{i: 8}
{i: 9}
{i: 10}
{i: 11}
{i: 12}
{i: 13}
{i: 14}
{i: 15}
{i: 16}
{i: 17}
{i: 18}
{i: 19}
{i: 20}
{i: 21}
{i: 22}
{i: 23}
{i: 24}
{i: 25}
{i: 26}
{i: 27}
{i: 28}
{i: 29}
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{i: 31}
{i: 32}
{i: 33}
{i: 34}
{i: 35}
{i: 36}
{i: 37}
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{i: 40}
{i: 41}
{i: 42}
{i: 43}
{i: 44}
{i: 45}
{i: 46}
{i: 47}
{i: 48}
{i: 49}
{i: 50}
{i: 51}
{i: 52}
{i: 53}
{i: 54}
{i: 55}
{i: 56}
{i: 57}
{i: 58}
{i: 59}
{i: 60}
{i: 61}
{i: 62}
{i: 63}
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{i: 65}
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{i: 84}
{i: 85}
{i: 86}
{i: 87}
{i: 88}
{i: 89}
{i: 90}
{i: 91}
{i: 92}
{i: 93}
{i: 94}
{i: 95}
{i: 96}
{i: 97}
{i: 98}
{i: 99}
{i: 100}
{i: 101}
{i: 102}
{i: 103}
{i: 104}
{i: 105}
{i: 106}
{i: 107}
{i: 108}
{i: 109}
{i: 110}
{i: 111}
{i: 112}
{i: 113}
{i: 114}
{i: 115}
{i: 116}
{i: 117}
{i: 118}
{i: 119}
{i: 120}
{i: 121}
{i: 122}
{i: 123}
{i: 124}
{i: 125}
{i: 126}
{i: 127}
{i: 128}
{i: 129}
{i: 130}
{i: 131}
{i: 132}
{i: 133}
{i: 134}
{i: 135}
{i: 136}
{i: 137}
{i: 138}
{i: 139}
{i: 140}
{i: 141}
{i: 142}
{i: 143}
#<Thread:0x000000010503d710 ./test.rb:1 run> terminated with exception (report_on_exception is true):
./test.rb:7:in 'Fiber.consume_stack': stack level too deep (SystemStackError)
  from ./test.rb:7:in 'block (2 levels) in <main>'
./test.rb:7:in 'Fiber.consume_stack': stack level too deep (SystemStackError)
  from ./test.rb:7:in 'block (2 levels) in <main>'
make: *** [runruby] Error 1
samuel@Sakura ~/D/i/ruby-darwin-check_overflow-fix (darwin-check_overflow-fix) [2]>