x/tools/internal/imports: TestIgnoreDocumentationPackage/GOPATH crash (ACCESS_VIOLATION due to nil fp in gopark)

[gopherbot]

#!watchflakes
default <- pkg == "golang.org/x/tools/internal/imports" && test == "TestIgnoreDocumentationPackage/GOPATH"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestIgnoreDocumentationPackage/GOPATH
Exception 0xc0000005 0x8 0x100000020 0x100000020
PC=0x100000020

runtime: g 18245 gp=0xc0005ace00: unknown pc 0x100000020
stack: frame={sp:0xc000229a38, fp:0x0} stack=[0xc000226000,0xc00022a000)
0x000000c000229938:  0x000000c0001ff008  0x000000c000229960 
0x000000c000229948:  0x000000014007d44e <runtime.gopark+0x00000000000000ce>  0x000000c000580068 
0x000000c000229958:  0x000000c0003263f0  0x000000c000229998 
0x000000c000229968:  0x0000000140028007 <runtime.gcParkAssist+0x00000000000000e7>  0x000000c00020cb68 
...
r11     0x246
r12     0xc000049908
r13     0x0
r14     0xc0005ace00
r15     0xb
rip     0x100000020
rflags  0x10207
cs      0x33
fs      0x53
gs      0x2b

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "golang.org/x/tools/internal/imports" && test == "TestIgnoreDocumentationPackage/GOPATH"

2025-03-31 18:54 x_tools-gotip-windows-amd64-race tools@5c9a69f9 go@b9cbb653 x/tools/internal/imports.TestIgnoreDocumentationPackage/GOPATH [ABORT] (log)

=== RUN   TestIgnoreDocumentationPackage/GOPATH
Exception 0xc0000005 0x8 0x100000020 0x100000020
PC=0x100000020

runtime: g 18245 gp=0xc0005ace00: unknown pc 0x100000020
stack: frame={sp:0xc000229a38, fp:0x0} stack=[0xc000226000,0xc00022a000)
0x000000c000229938:  0x000000c0001ff008  0x000000c000229960 
0x000000c000229948:  0x000000014007d44e <runtime.gopark+0x00000000000000ce>  0x000000c000580068 
0x000000c000229958:  0x000000c0003263f0  0x000000c000229998 
0x000000c000229968:  0x0000000140028007 <runtime.gcParkAssist+0x00000000000000e7>  0x000000c00020cb68 
...
r11     0x246
r12     0xc000049908
r13     0x0
r14     0xc0005ace00
r15     0xb
rip     0x100000020
rflags  0x10207
cs      0x33
fs      0x53
gs      0x2b

— watchflakes

[adonovan]

Looks like an ACCESS_VIOLATION (5) on Windows caused by a nil frame pointer in gopark. There seems to be plenty of stack space. (First time I've seen this particular form of stack dump. Is this a Windows thing?) Unfortunately I can't build the executable because -race requires a C toolchain, which means I can't cross-compile it from this mac.

Can any windows expert (@qmuntal?) or @golang/runtime person comment?

Exception 0xc0000005 0x8 0x100000020 0x100000020
PC=0x100000020

runtime: g 18245 gp=0xc0005ace00: unknown pc 0x100000020
stack: frame={sp:0xc000229a38, fp:0x0} stack=[0xc000226000,0xc00022a000)
0x000000c000229938:  0x000000c0001ff008  0x000000c000229960 
0x000000c000229948:  0x000000014007d44e <runtime.gopark+0x00000000000000ce>  0x000000c000580068 
0x000000c000229958:  0x000000c0003263f0  0x000000c000229998 
0x000000c000229968:  0x0000000140028007 <runtime.gcParkAssist+0x00000000000000e7>  0x000000c00020cb68 
0x000000c000229978:  0x000000c000f5e080  0x000000014000e725 <internal/stringslite.IndexByte+0x0000000000000025> 
0x000000c000229988:  0x000000c000229a28  0x000000c0005ace00 
0x000000c000229998:  0x000000c000229a28  0x000000014002780a <runtime.gcAssistAlloc+0x000000000000034a> 
0x000000c0002299a8:  0x000000c000229a00  0x00000001400f2879 <internal/filepathlite.replaceStringByte+0x0000000000000079> 
0x000000c0002299b8:  0x000000c0001da182  0x00000000000296c9 
0x000000c0002299c8:  0x000000c0002299f0  0x0000000140086d8c <sync/atomic.LoadInt64+0x000000000000000c> 
0x000000c0002299d8:  0x000000014008af11 <sync/atomic.LoadPointer+0x0000000000000011>  0x000000c000382e20 
0x000000c0002299e8:  0x000000c000229a48  0x000000014001b073 <runtime.mallocgcSmallScanNoHeader+0x0000000000000253> 
0x000000c0002299f8:  0x000000014009c725 <sync/atomic.(*Pointer[go.shape.struct { sync.poolDequeue; sync.next sync/atomic.Pointer[sync.poolChainElt]; sync.prev sync/atomic.Pointer[sync.poolChainElt] }]).Load+0x0000000000000045>  0x0000000140027aa0 <runtime.gcAssistAlloc.func2+0x0000000000000000> 
0x000000c000229a08:  0x000000c0005ace00  0x00000000000296c9 
0x000000c000229a18:  0x000003004008aca9  0x0000000000000000 
0x000000c000229a28:  0x000000c000229a48  0x0000000100000020 
0x000000c000229a38: <0x000000c0005ace00  0x000000c000008090 
0x000000c000229a48:  0x000000c000229a98  0x000000014007acc7 <runtime.mallocgc+0x0000000000000067> 
0x000000c000229a58:  0x0000000140643260  0x0000000000000000 
0x000000c000229a68:  0x0000000000000000  0x000000c000008090 
0x000000c000229a78:  0x0000000000000018  0x0000000000000018 
0x000000c000229a88:  0x000000c000008090  0x000000c000008090 
0x000000c000229a98:  0x000000c000229ac0  0x000000014007efa9 <runtime.makeslice+0x0000000000000049> 
0x000000c000229aa8:  0x0000000000010000  0x00000001406ca360 
0x000000c000229ab8:  0x0000000140096d01 <sync.(*Pool).Get+0x0000000000000081>  0x000000c000229af8 
0x000000c000229ac8:  0x0000000140108685 <os.init.func1+0x0000000000000045>  0x0000000000000000 
0x000000c000229ad8:  0x0000000000000000  0x0000000000000000 
0x000000c000229ae8:  0x000000c000229af8  0x000000c000008090 
0x000000c000229af8:  0x000000c000229b30  0x0000000140096d71 <sync.(*Pool).Get+0x00000000000000f1> 
0x000000c000229b08:  0x0000000140b76600  0x000000000000000a 
0x000000c000229b18:  0x0000000000000000  0x000000000000000a 
0x000000c000229b28:  0x0000000000000000  0x000000c000229d08 
runtime: g 18245 gp=0xc0005ace00: unknown pc 0x100000020

[gopherbot]

Change https://go.dev/cl/662575 mentions this issue: internal/syscall/windows: define NtQueryInformationFile buffer as unsafe.Pointer