cgo: runtime error: cgo argument has Go pointer to Go pointer

[eliasnaur]

From an android/386 build:

https://build.golang.org/log/96bfe68b3e3ad62f6721ab19f8f037beb3b347c9

--- FAIL: Test4029 (0.00s)
panic: runtime error: cgo argument has Go pointer to Go pointer
	panic: runtime error: cgo argument has Go pointer to Go pointer [recovered]
	panic: runtime error: cgo argument has Go pointer to Go pointer

goroutine 52 [running]:
testing.tRunner.func1(0xc7a287e0)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/src/testing/testing.go:742 +0x256
panic(0xe80a1300, 0xc7e3ba10)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/src/runtime/panic.go:505 +0x1f1
_/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test.loadThySelf.func1(0xe81bf237, 0x7e)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test/issue4029.go:59 +0x42
panic(0xe80a1300, 0xc7e3ba08)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/src/runtime/panic.go:505 +0x1f1
_/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test.loadThySelf.func2(0xe81bf237, 0xb7103000, 0xb7103000)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test/issue4029.go:61 +0x42
_/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test.loadThySelf(0xc7a287e0, 0xe801d9a6, 0xf)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test/issue4029.go:61 +0x82
_/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test.test4029(0xc7a287e0)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test/issue4029.go:44 +0x36
_/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test.Test4029(0xc7a287e0)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/misc/cgo/test/cgo_test.go:35 +0x1b
testing.tRunner(0xc7a287e0, 0xe80be3b8)
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/src/testing/testing.go:777 +0xb7
created by testing.(*T).Run
	/private/var/folders/f6/d2bhfqss2716nxm8gkv1fmb80000gn/T/workdir-host-darwin-amd64-eliasnaur-android/go/src/testing/testing.go:824 +0x25b

The only argument common to both the recovered panic and the panic from the deferred call is the this_process handle. It looks me as another instance of #21897, where the handle from dlopen is not a real pointer. CC @ianlancetaylor, @randall77.

[gopherbot]

Change https://golang.org/cl/91596 mentions this issue: misc/cgo/test: get uintptr, not pointer, from dlopen