debugging symbols and gdb

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

Trying to figure out why new-X is being flakey on my sandy bridge intel
laptop, I am suffering from lack of symbols.

I newfs'd /usr/obj, build.sh -x -E build, so binutils 2.31.1 should be
used throughout. Rebuilt /usr/src/external/mit/xorg/{server,lib} with

DBG=-ggdb -O2
MKSTRIPSYM=no
INSTALL_UNSTRIPPED=yes

Yet, no symbols in the backtrace:

# ls -l *core                      
-rw-------  1 root  wheel  26972072 Jan  3 14:47 X.core
# date                             
Thu Jan  3 14:48:00 GMT 2019            
# gdb `which Xorg` X.core          
GNU gdb (GDB) 8.0.1                     
...                                     
Reading symbols from /usr/X11R7/bin/Xorg...done.      
...                                       
Core was generated by `X'.                
Program terminated with signal SIGABRT, Aborted.      
#0  0x00007f7ff371efca in ?? ()
[Current thread is 1 (process 1)]                     
(gdb) bt                                              
#0  0x00007f7ff371efca in ?? ()                       
#1  0x00007f7ff371ec57 in ?? ()                     
#2  0xffffffffffffffdf in ?? ()
#3  0xffffffffffffffff in ?? ()
#4  0x0000000000428640 in ?? ()
#5  0x00000000003aee55 in ?? ()
#6  0x00007f7fffffe1b8 in ?? ()
#7  0x00000000003aa6bf in ?? ()
#8  0x00007f7ff5b565e0 in ?? ()
#9  0x00000000003ab358 in ?? ()
#10 0x0000003000000018 in ?? ()
#11 0x00007f7fffffe2a0 in ?? ()
#12 0x00007f7fffffe1d0 in ?? ()
#13 0x0000003000000008 in ?? ()
#14 0x00007f7fffffe2a0 in ?? ()
#15 0x00007f7fffffe1d0 in ?? ()
#16 0x00007f7fffffe2a0 in ?? ()
#17 0x000000000000000b in ?? ()
#18 0x00007f7ff396dbc0 in ?? ()         
#19 0x0000000000000000 in ?? ()
(gdb)                                   
                                        

Check for symbols:
# file /usr/X11R7/bin/Xorg 
/usr/X11R7/bin/Xorg: setuid ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /usr/libexec/ld.elf_so, for NetBSD 8.99.30, with debug_info, not stripped
# file /usr/X11R7/lib/libICE.so.7.0
/usr/X11R7/lib/libICE.so.7.0: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, for NetBSD 8.99.30, with debug_info, not stripped  

?

Cheers,

Patrick