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 <> wrote:

On Sat, Jan 25, 2020 at 8:51 AM Ludovic Courtès <> 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
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