C Parser is crashing with ruby-head debug builds

[casperisfine]

Describe the bug

We run our application test suite against Ruby nightly builds and recently we started seeing a crash on Ruby-head debug builds (built with RUBY_DEBUG=1)

/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/c_parser.rb:96: [BUG] Segmentation fault at 0x00007f1bd084ea18
ruby 3.3.0dev (2023-09-19T14:05:51Z shopify 5c5391f444) +YJIT [x86_64-linux]

-- Ruby level backtrace information ----------------------------------------
....
/bundle/ruby/3.3.0+0/gems/graphql-2.0.26/lib/graphql/query.rb:80:in `selected_operation_name'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-2.0.26/lib/graphql/query.rb:245:in `selected_operation'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-2.0.26/lib/graphql/query.rb:467:in `with_prepared_ast'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-2.0.26/lib/graphql/query.rb:407:in `prepare_ast'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-2.0.26/lib/graphql.rb:46:in `parse'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/c_parser.rb:11:in `parse'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/c_parser.rb:95:in `result'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-shopify-0.9.0/lib/graphql/shopify/trace.rb:21:in `parse'
...
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/c_parser.rb:96:in `block in result'
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/c_parser.rb:96:in `c_parse'

-- Threading information ---------------------------------------------------
Total ractor count: 1
Ruby thread count for this ractor: 6

-- Machine register context ------------------------------------------------
 RIP: 0x000055bf456cf438 RBP: 0x00007f1bd084ea10 RSP: 0x00007ffc475948c0
 RAX: 0x0000000000000000 RBX: 0x00007f1bcdd6c6e0 RCX: 0x0000000000000004
 RDX: 0x0000000000091f11 RDI: 0x00007f1bd084ea10 RSI: 0x0000000000000000
  R8: 0x0000000000000000  R9: 0x0000000000000000 R10: 0x0000000000000000
 R11: 0x00007f1a84c43c20 R12: 0x0000000000000004 R13: 0x00007f1bdd684050
 R14: 0x0000000000091f11 R15: 0x00007f1a84c43c20 EFL: 0x0000000000010202

-- C level backtrace information -------------------------------------------
/usr/local/ruby/bin/ruby(rb_print_backtrace+0x14) [0x55bf456f781a] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_dump.c:772
/usr/local/ruby/bin/ruby(rb_vm_bugreport) /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_dump.c:1088
/usr/local/ruby/bin/ruby(rb_bug_for_fatal_signal+0xee) [0x55bf4587c9ee] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/error.c:819
/usr/local/ruby/bin/ruby(sigsegv+0x4d) [0x55bf4564cb0d] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/signal.c:920
/lib/x86_64-linux-gnu/libc.so.6(0x7f1bddd33520) [0x7f1bddd33520]
/usr/local/ruby/bin/ruby(RBASIC_CLASS+0x0) [0x55bf456cf438] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_callinfo.h:599
/usr/local/ruby/bin/ruby(gccct_method_search) /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_eval.c:471
/usr/local/ruby/bin/ruby(rb_funcallv_scope+0x23) [0x55bf456e3230] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_eval.c:1059
/usr/local/ruby/bin/ruby(rb_funcallv) /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_eval.c:1080
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/graphql_c_parser_ext.so(yyparse+0x1f68) [0x7f1bcdd656a8] graphql-c_parser/ext/graphql_c_parser_ext/parser.y:342
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/graphql_c_parser_ext.so(yyparse) (null):0
/tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/lib/graphql/graphql_c_parser_ext.so(GraphQL_CParser_Parser_c_parse+0x4f) [0x7f1bcdd6067f] /tmp/bundle/ruby/3.3.0+0/gems/graphql-c_parser-1.0.5/ext/graphql_c_parser_ext/graphql_c_parser_ext.c:8
/usr/local/ruby/bin/ruby(vm_call_cfunc_with_frame_+0x10b) [0x55bf456d4d5b] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_insnhelper.c:3475
/usr/local/ruby/bin/ruby(vm_sendish+0x16a) [0x55bf456cda4a] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm_insnhelper.c:5553
/usr/local/ruby/bin/ruby(vm_exec_core+0xa5) [0x55bf456e7425] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/insns.def:835
/usr/local/ruby/bin/ruby(rb_vm_exec+0x1d3) [0x55bf456d9183] /tmp/ruby-build/ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7/vm.c:2401
[0x55bf4ac52127]

Versions

• graphql-c_parser-1.0.5
• ruby-3.3.0-5c5391f444624bcee6a258bcc7b4777c7c295ae7 (with RUBY_DEBUG=1, without seem fine)
• graphql-2.0.26

Steps to reproduce

I haven't had to time to work out a reduced reproduction script yet, I'm mostly giving advance notice in case the bug seem obvious to the author.

Expected behavior

No crash.

Actual behavior

Crash.

[casperisfine]

I struggled a bit to run the project test suite locally with the C Parser, but after figuring it out it revealed a bunch of very suspicious errors:

Error:
GraphQL::Dataloader::AsyncDataloader::With the toy scheduler from Ruby's tests#test_0003_works with GraphQL:
NotImplementedError: method `hash' called on hidden T_FILE object (0x0000000119cd5ca0 flags=0xb)
    src/graphql-ruby/spec/support/dummy_scheduler.rb:159:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in `sleep'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `public_send'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `block (2 levels) in resolve'
    src/graphql-ruby/lib/graphql/schema/field.rb:832:in `with_extensions'
    src/graphql-ruby/lib/graphql/schema/field.rb:669:in `block in resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:955:in `minimal_after_lazy'
    src/graphql-ruby/lib/graphql/query.rb:366:in `after_lazy'
    src/graphql-ruby/lib/graphql/schema/field.rb:667:in `resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:541:in `block (2 levels) in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/tracing/trace.rb:51:in `execute_field'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:540:in `block in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:894:in `call_method_on_directives'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:537:in `evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:513:in `block in evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:1013:in `after_lazy'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:461:in `evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:455:in `block in evaluate_selection'
    src/graphql-ruby/lib/graphql/execution/interpreter/arguments_cache.rb:51:in `block in dataload_for'
    src/graphql-ruby/lib/graphql/schema/member/has_arguments.rb:300:in `block (3 levels) in coerce_arguments'
    src/graphql-ruby/lib/graphql/dataloader.rb:190:in `block in run'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::With the toy scheduler from Ruby's tests#test_0001_runs IO in parallel by default:
NotImplementedError: method `hash' called on hidden T_FILE object (0x0000000119cd1680 flags=0xb)
    src/graphql-ruby/spec/support/dummy_scheduler.rb:159:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:101:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:101:in `block (3 levels) in included'
    src/graphql-ruby/lib/graphql/dataloader.rb:190:in `block in run'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::With the toy scheduler from Ruby's tests#test_0005_runs dataloaders in parallel across branches:
NotImplementedError: method `hash' called on hidden T_FILE object (0x0000000119c75ee0 flags=0xb)
    src/graphql-ruby/spec/support/dummy_scheduler.rb:159:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:23:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:23:in `fetch'
    src/graphql-ruby/lib/graphql/dataloader/source.rb:135:in `run_pending_keys'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `each'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `block in create_source_fiber'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::With the toy scheduler from Ruby's tests#test_0002_works with sources:
NotImplementedError: method `hash' called on hidden T_FILE object (0x0000000119c5e990 flags=0xb)
    src/graphql-ruby/spec/support/dummy_scheduler.rb:159:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:10:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:10:in `fetch'
    src/graphql-ruby/lib/graphql/dataloader/source.rb:135:in `run_pending_keys'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `each'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `block in create_source_fiber'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::With the toy scheduler from Ruby's tests#test_0004_nested fields don't wait for slower higher-level fields:
NotImplementedError: method `hash' called on hidden T_FILE object (0x0000000119c35da0 flags=0xb)
    src/graphql-ruby/spec/support/dummy_scheduler.rb:159:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in `sleep'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `public_send'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `block (2 levels) in resolve'
    src/graphql-ruby/lib/graphql/schema/field.rb:832:in `with_extensions'
    src/graphql-ruby/lib/graphql/schema/field.rb:669:in `block in resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:955:in `minimal_after_lazy'
    src/graphql-ruby/lib/graphql/query.rb:366:in `after_lazy'
    src/graphql-ruby/lib/graphql/schema/field.rb:667:in `resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:541:in `block (2 levels) in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/tracing/trace.rb:51:in `execute_field'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:540:in `block in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:894:in `call_method_on_directives'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:537:in `evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:513:in `block in evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:1013:in `after_lazy'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:461:in `evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:455:in `block in evaluate_selection'
    src/graphql-ruby/lib/graphql/execution/interpreter/arguments_cache.rb:51:in `block in dataload_for'
    src/graphql-ruby/lib/graphql/schema/member/has_arguments.rb:300:in `block (3 levels) in coerce_arguments'
    src/graphql-ruby/lib/graphql/dataloader.rb:190:in `block in run'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::with evt#test_0002_works with sources:
NotImplementedError: method `hash' called on hidden T_FILE object (0x000000011ae1edf0 flags=0xb)
    /Users/byroot/.gem/ruby/3.3.0/gems/evt-0.4.0/lib/evt/backends/bundled.rb:100:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:10:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:10:in `fetch'
    src/graphql-ruby/lib/graphql/dataloader/source.rb:135:in `run_pending_keys'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `each'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `block in create_source_fiber'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::with evt#test_0001_runs IO in parallel by default:
NotImplementedError: method `hash' called on hidden T_FILE object (0x000000011ae1b880 flags=0xb)
    /Users/byroot/.gem/ruby/3.3.0/gems/evt-0.4.0/lib/evt/backends/bundled.rb:100:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:101:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:101:in `block (3 levels) in included'
    src/graphql-ruby/lib/graphql/dataloader.rb:190:in `block in run'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::with evt#test_0003_works with GraphQL:
NotImplementedError: method `hash' called on hidden T_FILE object (0x000000011adfae80 flags=0xb)
    /Users/byroot/.gem/ruby/3.3.0/gems/evt-0.4.0/lib/evt/backends/bundled.rb:100:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in `sleep'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `public_send'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `block (2 levels) in resolve'
    src/graphql-ruby/lib/graphql/schema/field.rb:832:in `with_extensions'
    src/graphql-ruby/lib/graphql/schema/field.rb:669:in `block in resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:955:in `minimal_after_lazy'
    src/graphql-ruby/lib/graphql/query.rb:366:in `after_lazy'
    src/graphql-ruby/lib/graphql/schema/field.rb:667:in `resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:541:in `block (2 levels) in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/tracing/trace.rb:51:in `execute_field'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:540:in `block in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:894:in `call_method_on_directives'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:537:in `evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:513:in `block in evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:1013:in `after_lazy'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:461:in `evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:455:in `block in evaluate_selection'
    src/graphql-ruby/lib/graphql/execution/interpreter/arguments_cache.rb:51:in `block in dataload_for'
    src/graphql-ruby/lib/graphql/schema/member/has_arguments.rb:300:in `block (3 levels) in coerce_arguments'
    src/graphql-ruby/lib/graphql/dataloader.rb:190:in `block in run'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::with evt#test_0005_runs dataloaders in parallel across branches:
NotImplementedError: method `hash' called on hidden T_FILE object (0x000000011ab7dc80 flags=0xb)
    /Users/byroot/.gem/ruby/3.3.0/gems/evt-0.4.0/lib/evt/backends/bundled.rb:100:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:23:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:23:in `fetch'
    src/graphql-ruby/lib/graphql/dataloader/source.rb:135:in `run_pending_keys'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `each'
    src/graphql-ruby/lib/graphql/dataloader.rb:278:in `block in create_source_fiber'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

Error:
GraphQL::Dataloader::AsyncDataloader::with evt#test_0004_nested fields don't wait for slower higher-level fields:
NotImplementedError: method `hash' called on hidden T_FILE object (0x000000011b19ee90 flags=0xb)
    /Users/byroot/.gem/ruby/3.3.0/gems/evt-0.4.0/lib/evt/backends/bundled.rb:100:in `io_wait'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in ``'
    src/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb:69:in `sleep'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `public_send'
    src/graphql-ruby/lib/graphql/schema/field.rb:698:in `block (2 levels) in resolve'
    src/graphql-ruby/lib/graphql/schema/field.rb:832:in `with_extensions'
    src/graphql-ruby/lib/graphql/schema/field.rb:669:in `block in resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:955:in `minimal_after_lazy'
    src/graphql-ruby/lib/graphql/query.rb:366:in `after_lazy'
    src/graphql-ruby/lib/graphql/schema/field.rb:667:in `resolve'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:541:in `block (2 levels) in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/tracing/trace.rb:51:in `execute_field'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:540:in `block in evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:894:in `call_method_on_directives'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:537:in `evaluate_selection_with_resolved_keyword_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:513:in `block in evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:1013:in `after_lazy'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:461:in `evaluate_selection_with_args'
    src/graphql-ruby/lib/graphql/execution/interpreter/runtime.rb:455:in `block in evaluate_selection'
    src/graphql-ruby/lib/graphql/execution/interpreter/arguments_cache.rb:51:in `block in dataload_for'
    src/graphql-ruby/lib/graphql/schema/member/has_arguments.rb:300:in `block (3 levels) in coerce_arguments'
    src/graphql-ruby/lib/graphql/dataloader.rb:190:in `block in run'
    src/graphql-ruby/lib/graphql/dataloader.rb:310:in `block in spawn_fiber'

At a glance this looks like a GC issue, probably an unmarked reference.

[casperisfine]

Actually none of the above seem to involve the parser.

[casperisfine]

Ok, I believe I found the issue:

(gdb) p *(RBasic *)GraphQL_Language_Nodes_NONE
$15 = {flags = 42949683495, klass = 140002193826816}
(gdb) p *(RBasic *)GraphQL_Language_Nodes_Argument
Cannot access memory at address 0x7f54c1b9e5a0

GraphQL_Language_Nodes_NONE is properly registered with rb_global_variable, but all other GraphQL_Language_Nodes_ aren't.

I'll submit a PR, but I'm having a bit of a trouble building the extension locally because of ragel and Bison requirements.

[casperisfine]

Note, the test failures in evt are likely of the same nature:

NotImplementedError: method `hash' called on hidden T_FILE object (0x000000011adfae80 flags=0xb)
    /Users/byroot/.gem/ruby/3.3.0/gems/evt-0.4.0/lib/evt/backends/bundled.rb:100:in `io_wait'

evt clearly fails to mark a reference, and it end up replaced by another object.

[casperisfine]

Note, the test failures in evt are likely of the same nature:

Nevermind, the faulty object is the one recieved as argument from graphql so the bug must be in GraphQL.

[casperisfine]

Interesting. With allocation tracing on, It appears the Hidden FILE is allocated by:

`sleep #{max_wait}`

E{"address":"0x15d8dbde0", "type":"FILE", "shape_id":0, "slot_size":40, "fd":14, "references":["0x15d8dbde0"], "file":"/Users/byroot/src/github.com/casperisfine/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb", "line":23, "method":"`", "generation":83, "memsize":248}
E{"address":"0x15d8daca0", "type":"FILE", "shape_id":0, "slot_size":40, "fd":16, "references":["0x15d8daca0"], "file":"/Users/byroot/src/github.com/casperisfine/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb", "line":10, "method":"`", "generation":83, "memsize":248}
E{"address":"0x15d8d6860", "type":"FILE", "shape_id":0, "slot_size":40, "fd":18, "references":["0x15d8d6860"], "file":"/Users/byroot/src/github.com/casperisfine/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb", "line":69, "method":"`", "generation":83, "memsize":248}
E{"address":"0x15d8d5b70", "type":"FILE", "shape_id":0, "slot_size":40, "fd":20, "references":["0x15d8d5b70"], "file":"/Users/byroot/src/github.com/casperisfine/graphql-ruby/spec/graphql/dataloader/async_dataloader_spec.rb", "line":101, "method":"`", "generation":83, "memsize":248}

So this might actually be a bug in Ruby, I'll report it to the owner.

[casperisfine]

Ok, I git a fix for it ruby/ruby#8485

[rmosolgo]

Thanks for sharing all your research on this 👍