cmd/cgo/internal/test: TestCthread failures

[gopherbot]

#!watchflakes
default <- pkg == "cmd/cgo/internal/test" && test == "TestCthread"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestCthread
Exception 0x200c7 0xecd54de8 0xcc483ff 0x0
PC=0x0

fatal error: unexpected signal during runtime execution
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x91588e]

runtime stack:
runtime.throw({0xa78c85, 0x2a})
	C:/b/s/w/ir/x/w/goroot/src/runtime/panic.go:1108 +0x35 fp=0x2acefa14 sp=0x2acefa00 pc=0x927b25
...
	C:/b/s/w/ir/x/w/goroot/src/runtime/proc.go:435 +0xfd fp=0x19bdf8c sp=0x19bdf78 pc=0x927c5d
runtime.gcBgMarkWorker(0x19949c0)
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1432 +0xe2 fp=0x19bdfe8 sp=0x19bdf8c pc=0x8cf882
runtime.gcBgMarkStartWorkers.gowrap1()
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1348 +0x25 fp=0x19bdff0 sp=0x19bdfe8 pc=0x8cf785
runtime.goexit({})
	C:/b/s/w/ir/x/w/goroot/src/runtime/asm_386.s:1393 +0x1 fp=0x19bdff4 sp=0x19bdff0 pc=0x92d731
created by runtime.gcBgMarkStartWorkers in goroutine 69
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1348 +0x11a
*** Test killed: ran too long (4m0s).

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/cgo/internal/test" && test == "TestCthread"

2025-02-18 17:28 gotip-windows-386 go@0bdc7921 cmd/cgo/internal/test.TestCthread [ABORT] (log)

=== RUN   TestCthread
Exception 0x200c7 0xecd54de8 0xcc483ff 0x0
PC=0x0

fatal error: unexpected signal during runtime execution
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x91588e]

runtime stack:
runtime.throw({0xa78c85, 0x2a})
	C:/b/s/w/ir/x/w/goroot/src/runtime/panic.go:1108 +0x35 fp=0x2acefa14 sp=0x2acefa00 pc=0x927b25
...
	C:/b/s/w/ir/x/w/goroot/src/runtime/proc.go:435 +0xfd fp=0x19bdf8c sp=0x19bdf78 pc=0x927c5d
runtime.gcBgMarkWorker(0x19949c0)
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1432 +0xe2 fp=0x19bdfe8 sp=0x19bdf8c pc=0x8cf882
runtime.gcBgMarkStartWorkers.gowrap1()
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1348 +0x25 fp=0x19bdff0 sp=0x19bdfe8 pc=0x8cf785
runtime.goexit({})
	C:/b/s/w/ir/x/w/goroot/src/runtime/asm_386.s:1393 +0x1 fp=0x19bdff4 sp=0x19bdff0 pc=0x92d731
created by runtime.gcBgMarkStartWorkers in goroutine 69
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1348 +0x11a
*** Test killed: ran too long (4m0s).

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/cgo/internal/test" && test == "TestCthread"

2025-08-21 18:41 gotip-windows-386 go@9b0a5077 cmd/cgo/internal/test.TestCthread [SKIP] (log)

=== RUN   TestCthread
Exception 0x200c7 0xeca66de8 0xcc483ff 0x0
PC=0x0

fatal error: unexpected signal during runtime execution
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x1793ae]

runtime stack:
runtime.throw({0x2e2c1e, 0x2a})
	C:/b/s/w/ir/x/w/goroot/src/runtime/panic.go:1227 +0x35 fp=0x2a72f574 sp=0x2a72f560 pc=0x18bdb5
...
	C:/b/s/w/ir/x/w/goroot/src/runtime/proc.go:460 +0xfd fp=0x15c3f8c sp=0x15c3f78 pc=0x18beed
runtime.gcBgMarkWorker(0x1594140)
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1463 +0xe4 fp=0x15c3fe8 sp=0x15c3f8c pc=0x132e04
runtime.gcBgMarkStartWorkers.gowrap1()
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1373 +0x1e fp=0x15c3ff0 sp=0x15c3fe8 pc=0x132d0e
runtime.goexit({})
	C:/b/s/w/ir/x/w/goroot/src/runtime/asm_386.s:1386 +0x1 fp=0x15c3ff4 sp=0x15c3ff0 pc=0x191c91
created by runtime.gcBgMarkStartWorkers in goroutine 64
	C:/b/s/w/ir/x/w/goroot/src/runtime/mgc.go:1373 +0x11a
*** Test killed: ran too long (4m0s).

— watchflakes