Le 01/09/2020 à 19:15, Stefan Kangas a écrit :
> Eli Zaretskii <eliz@gnu.org> writes:
>
>>>       Unable to find Mach task port for process-id 19495: (os/kern)
>>> failure (0x5).
>> This is macOS, where one cannot use GDB without some jumping through
>> hoops, sigh.
> It's not too bad, IMHO.  Here are the instructions from etc/DEBUG:
>
>      Running GDB on macOS sometimes brings an error message like this:
>
>        Unable to find Mach task port for process-id NNN: (os/kern) failure (0x5).
>
>      To overcome this, search the Internet for the phrase "Unable to find
>      Mach task port for process-id", and you will find detailed
>      instructions to follow.
>
> Best regards,
> Stefan Kangas

Here is backtrace running with gdb

     spungen:src $ gdb ./temacs
     GNU gdb (GDB) 8.0.1
     Copyright (C) 2017 Free Software Foundation, Inc.
     License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
     This is free software: you are free to change and redistribute it.
     There is NO WARRANTY, to the extent permitted by law.  Type "show 
copying"
     and "show warranty" for details.
     This GDB was configured as "x86_64-apple-darwin17.0.0".
     Type "show configuration" for configuration details.
     For bug reporting instructions, please see:
     <http://www.gnu.org/software/gdb/bugs/>.
     Find the GDB manual and other documentation resources online at:
     <http://www.gnu.org/software/gdb/documentation/>.
     For help, type "help".
     Type "apropos word" to search for commands related to "word"...
     Reading symbols from ./temacs...
     warning: can't find symbol 'l_OBJC_PROTOCOL_$_NSMenuDelegate' in 
minsymtab

     warning: can't find symbol 'l_OBJC_PROTOCOL_$_NSObject' in minsymtab

     warning: can't find symbol 'l_OBJC_PROTOCOL_$_NSToolbarDelegate' in 
minsymtab

     warning: can't find symbol 'l_OBJC_PROTOCOL_$_NSWindowDelegate' in 
minsymtab
     done.
     SIGINT is used by the debugger.
     Are you sure you want to change it? (y or n) [answered Y; input not 
from terminal]
     DISPLAY = 
/private/tmp/com.apple.launchd.NmbcYXYKys/org.macosforge.xquartz:0
     TERM = xterm-color
     Breakpoint 1 at 0x1000d1562: file emacs.c, line 378.
     (gdb) run --batch  -l loadup --temacs=pbootstrap
     Starting program: /usr/local/src/emacs/src/temacs --batch  -l 
loadup --temacs=pbootstrap
     [New Thread 0x1903 of process 507]
     warning: unhandled dyld version (15)
     [New Thread 0x1a03 of process 507]
     [New Thread 0x2603 of process 507]
     [New Thread 0x2807 of process 507]

     Thread 2 received signal SIGSEGV, Segmentation fault.
     0x00007fff7bc4498d in ?? ()
     (gdb) where
     #0  0x00007fff7bc4498d in ?? ()
     #1  0x000000003272002e in ?? ()
     #2  0x0000000102c05380 in ?? ()
     #3  0x00007ffeefbff5c0 in ?? ()
     #4  0x000000010010908e in Ffile_name_as_directory 
(file=XIL(0x102c05384)) at fileio.c:563
     Backtrace stopped: previous frame inner to this frame (corrupt stack?)
     (gdb) quit
     A debugging session is active.

     Inferior 1 [process 507] will be killed.

     Quit anyway? (y or n) y

I rebuild with more options to configure :

     --enable-checking='yes,glyphs' --enable-check-lisp-object-type \
         CFLAGS='-O0 -g3

with same backtrace.

Best regards

-- 

	Philippe Spiesser