bug#39118: Segfault while building on 64-bit Cygwin

Aaaand... Cygwin doesn't do core dumps. Under the skin it's WIndows, after
all.  This is what I get when I specify ulimit -c unlimited and rebuild:

Exception: STATUS_ACCESS_VIOLATION at rip=0055A8B1B25
rax=0000000000000000 rbx=FFFFFFFFFFFFFF90 rcx=FFFFFFFFFFFFFF90
rdx=000000000034964A rsi=000007000084ECC0 rdi=FFFFFFFFFFFFFF90
r8 =000007000084ECC0 r9 =0000000000000002 r10=0000000100000000
r11=000000055A86B190 r12=0000000000000002 r13=000000055A931EA0
r14=000006FFFFFEF840 r15=0000000000000000
rbp=000000000034964A rsp=00000000FFFFBDA0
program=C:\Users\rr828893\Downloads\guile-3.0.0\libguile\.libs\guile.exe,
pid 62833, thread main
cs=0033 ds=002B es=002B fs=0053 gs=002B ss=002B

I can't imagine what you can make of that.

On Sat, Jan 25, 2020 at 10:54 AM John Cowan <[email protected]> wrote:

>
>
> On Sat, Jan 25, 2020 at 8:51 AM Ludovic Courtès <[email protected]> wrote:
>
>
>> That I understand.  However, I was asking for the backtrace of the crash
>> on Cygwin when JIT is enabled.  Could you grab it?
>>
>
> 1. The wisdom of the Internet has not been able to figure out how to
> generate a core dump on MacOS 10.15.2 (Catalina).  The usual set of
> enabling steps can be performed without error, but still no core dump.
>
> 2. Until today I believed that there was no way to generate a Cygwin core
> dump.  I know now that there is, but I may not be able to test it until
> Monday.  I'll let you know, and hopefully that will provide insight into
> the MacOS problem as well.
>
> 3.  I will try to work further on the MacOS libffi problem (which surfaces
> when you do --disable-jit to bypass the above problem) to convince MacOS to
> use GNU libffi rather than the native one.  It probably has to do with
> pkg-config, which I barely understand.
>
> "All problems are config problems."
>
>
>
> John Cowan          http://vrici.lojban.org/~cowan        [email protected]
> We are lost, lost.  No name, no business, no Precious, nothing.  Only
> empty.
> Only hungry: yes, we are hungry.  A few little fishes, nassty bony little
> fishes, for a poor creature, and they say death.  So wise they are; so
> just,
> so very just.  --Gollum
>