GC root erroring in subtype?

[vtjnash]

      From worker 12:
      From worker 12:	Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.
      From worker 12:	Exception: EXCEPTION_ACCESS_VIOLATION at 0x7ffc88df24d9 -- has_free_typevars at C:/workdir/src\jltypes.c:110
      From worker 12:	in expression starting at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\subtype.jl:1108
      From worker 12:	has_free_typevars at C:/workdir/src\jltypes.c:110
      From worker 12:	ijl_has_free_typevars at C:/workdir/src\jltypes.c:158 [inlined]
      From worker 12:	jl_precompute_memoized_dt at C:/workdir/src\jltypes.c:1646
      From worker 12:	inst_datatype_inner at C:/workdir/src\jltypes.c:2035
      From worker 12:	jl_apply_tuple_type_v_ at C:/workdir/src\jltypes.c:2091 [inlined]
      From worker 12:	ijl_apply_tuple_type_v at C:/workdir/src\jltypes.c:2101
      From worker 12:	macro expansion at C:\workdir\usr\share\julia\stdlib\v1.10\Test\src\Test.jl:512 [inlined]
      From worker 12:	test_properties at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\subtype.jl:683
      From worker 12:	unknown function (ip: 000002c3af7d3903)
      From worker 12:	jl_apply at C:/workdir/src\julia.h:1961 [inlined]
      From worker 12:	do_call at C:/workdir/src\interpreter.c:125
      From worker 12:	eval_value at C:/workdir/src\interpreter.c:222
      From worker 12:	eval_stmt_value at C:/workdir/src\interpreter.c:173 [inlined]
      From worker 12:	eval_body at C:/workdir/src\interpreter.c:620
      From worker 12:	jl_interpret_toplevel_thunk at C:/workdir/src\interpreter.c:760
      From worker 12:	jl_toplevel_eval_flex at C:/workdir/src\toplevel.c:911
      From worker 12:	jl_toplevel_eval_flex at C:/workdir/src\toplevel.c:854
      From worker 12:	ijl_toplevel_eval at C:/workdir/src\toplevel.c:920 [inlined]
      From worker 12:	ijl_toplevel_eval_in at C:/workdir/src\toplevel.c:970
      From worker 12:	eval at .\boot.jl:383 [inlined]
      From worker 12:	include_string at .\loading.jl:1945
      From worker 12:	_include at .\loading.jl:2005
      From worker 12:	include at .\Base.jl:488 [inlined]
      From worker 12:	macro expansion at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\testdefs.jl:29 [inlined]
      From worker 12:	macro expansion at C:\workdir\usr\share\julia\stdlib\v1.10\Test\src\Test.jl:1546 [inlined]
      From worker 12:	macro expansion at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\testdefs.jl:23 [inlined]
      From worker 12:	macro expansion at .\timing.jl:501 [inlined]
      From worker 12:	#runtests#3 at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\testdefs.jl:21
      From worker 12:	runtests at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\testdefs.jl:5 [inlined]
      From worker 12:	runtests at C:\buildkite-agent\builds\win2k22-amdci6-4\julialang\julia-master\julia-540f283cb3\share\julia\test\testdefs.jl:5
      From worker 12:	unknown function (ip: 000002c3d1cdcb72)
      From worker 12:	jl_apply at C:/workdir/src\julia.h:1961 [inlined]
      From worker 12:	jl_f__call_latest at C:/workdir/src\builtins.c:812
      From worker 12:	jl_apply at C:/workdir/src\julia.h:1961 [inlined]
      From worker 12:	do_apply at C:/workdir/src\builtins.c:768
      From worker 12:	#invokelatest#2 at .\essentials.jl:865
      From worker 12:	jl_apply at C:/workdir/src\julia.h:1961 [inlined]
      From worker 12:	do_apply at C:/workdir/src\builtins.c:768
      From worker 12:	invokelatest at .\essentials.jl:860
      From worker 12:	jl_apply at C:/workdir/src\julia.h:1961 [inlined]
      From worker 12:	do_apply at C:/workdir/src\builtins.c:768
      From worker 12:	#110 at C:\workdir\usr\share\julia\stdlib\v1.10\Distributed\src\process_messages.jl:285
      From worker 12:	run_work_thunk at C:\workdir\usr\share\julia\stdlib\v1.10\Distributed\src\process_messages.jl:70
      From worker 12:	#109 at C:\workdir\usr\share\julia\stdlib\v1.10\Distributed\src\process_messages.jl:285
      From worker 12:	unknown function (ip: 000002c3d1cd4383)
      From worker 12:	jl_apply at C:/workdir/src\julia.h:1961 [inlined]
      From worker 12:	start_task at C:/workdir/src\task.c:1238
      From worker 12:	Allocations: 250174524 (Pool: 249846051; Big: 328473); GC: 348
Worker 12 terminated.

https://buildkite.com/julialang/julia-master/builds/23764#0188077d-f957-45a8-ad20-baed893dbb4d
test x86_64-w64-mingw32

[vtjnash]

Now with rr log: https://buildkite.com/julialang/julia-master/builds/23864#0188108b-66d3-4887-90c2-3cf349bf2f44

[vtjnash]

We are on this line

 681                 @test issubTS == issub(Tuple{T}, Tuple{S})

with T=Tuple{T, S} where S<:Number where T<:Integer
this results in calling

1847                iparams[i] = normalize_unionalls(iparams[i]);                                                       

to turn it into
T=Tuple{Integer, Number}
but then we free (unmap) iparam[0] (since it wasn't rooted during the call to ijl_alloc_svec_uninit, which happens next), which then causes a null pointer exception when we try to figure out the properties of Tuple{Tuple{Integer, Number}} in jl_precompute_memoized_dt shortly thereafter.
This iparams originally came from here:

1355            return jl_apply_tuple_type_v(&args[1], nargs-1);