call to gc.cleanupThread(thread); seg faults at rmem.d line 535

[WalterBright]

With dmd for the Mac OSX x86_64 build.

The pull request that added it: https://github.com/dlang/dmd/pull/232874

Target 0: (dmdxxx) stopped.
warning: This version of LLDB has no plugin for the language "d". Inspection of frame variables will be limited.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
  * frame #0: 0x0000000100072680 dmdxxx`_D3dmd4root4rmem13BumpPointerGC13cleanupThreadMFNbNiC4core6thread10threadbase10ThreadBaseZv(this=0x00000001006af6a0, thread=0x00000001006dc358) at rmem.d:535
    frame #1: 0x00000001004918e6 dmdxxx`_D4core6thread8osthread6Thread6__dtorMFNbNiNlZv + 42
    frame #2: 0x00000001004929e2 dmdxxx`thread_term + 38
    frame #3: 0x0000000100493b00 dmdxxx`rt_term + 88
    frame #4: 0x0000000100494171 dmdxxx`_D2rt6dmain212_d_run_main2UAAamPUQgZiZ6runAllMFZv + 201
    frame #5: 0x000000010049405a dmdxxx`_D2rt6dmain212_d_run_main2UAAamPUQgZiZ7tryExecMFMDFZvZv + 34
    frame #6: 0x0000000100493fcc dmdxxx`_d_run_main2 + 476
    frame #7: 0x0000000100493dd4 dmdxxx`_d_run_main + 184
    frame #8: 0x0000000100000871 dmdxxx`main(argc=1, argv=0x0000000304e3c788) at main.d:111
    frame #9: 0x0000000200d27530 dyld`start + 3056
(lldb) ^C

ping @rainers

[WalterBright]

Corrected PR link: #23287

[rikkimax]

Can you please confirm that it is the gc field that is null?

Also please put a print into the destructor, which could be firing and kill the field.

[rainers]

@WalterBright what host compiler version are you using?

[rainers]

From your call stack it seems that thread termination is calling the GC cleanupThread function from within thread_term after the GC has already been deleted:

dmd/druntime/src/rt/dmain2.d

Lines 162 to 163 in 35657bf

	gc_term();
	thread_term();

but I don't see this anywhere in the source code, neither in master nor in dmd 2.112 that introduced cleanupThread.

Are you compiling dmd with a modified druntime?

[WalterBright]

@rikkimax printing the thread value yields:

thread: 0x10293a398
Segmentation fault: 11

so it is not null.

[WalterBright]

Are you compiling dmd with a modified druntime?

No, I'm using master. My dmd builds started breaking about the time this was merged.

[WalterBright]

I've been using DMD64 D Compiler v2.112.0-beta.1 as my bootstrap compiler.

[rainers]

v2.112.0-beta.1 can be a pretty large range of versions. I suspect your host compiler misses this change #22067, please update to a release version.

[WalterBright]

thanks I'll try it tomorrow