*gdb* to the rescue: derick@whisky:~/docs/debugging-demo $ *gdb --args php gdb1/bug01180.php* GNU gdb (Debian 7.10-1+b1) 7.10 Copyright (C) 2015 Free Software Foundation, Inc. … For help, type "help". Type "apropos word" to search for commands related to "word"... *Reading symbols from php...(no debugging symbols found)...done.* (gdb) run Starting program: */usr/php/7.0dev-nodebug/bin/php gdb1/bug01180.php* [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". *Program received signal SIGSEGV, Segmentation fault.* *__strcmp_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strcmp-sse2-unaligned.S:32* *32 ../sysdeps/x86_64/multiarch/strcmp-sse2-unaligned.S: No such file or directory.* (gdb)

(gdb) *bt full* #0 __strcmp_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strcmp-sse2-unaligned.S:32 *No locals.* #1 0x00007fffed6d672d in xdebug_branch_info_mark_end_of_function_reached *()* from /usr/php/7.0dev-nodebug/lib/php/extensions/no-debug-non-zts-20151012/xdebug.so *No symbol table info available.* #2 0x00007fffed6d910a in xdebug_code_coverage_end_of_function () from /usr/php/7.0dev-nodebug/lib/php/extensions/no-debug-non-zts-20151012/xdebug.so No symbol table info available. #3 0x00007fffed6d3664 in xdebug_execute_ex () from /usr/php/7.0dev-nodebug/lib/php/extensions/no-debug-non-zts-20151012/xdebug.so No symbol table info available. #4 0x00000000008e0e2d in *?? ()* No symbol table info available. #5 0x000000000089cbbb in execute_ex () No symbol table info available. #6 0x00007fffed6d35ff in xdebug_execute_ex () from /usr/php/7.0dev-nodebug/lib/php/extensions/no-debug-non-zts-20151012/xdebug.so No symbol table info available. #7 0x00000000008e0e2d in ?? () No symbol table info available. ---Type <return> to continue, or q <return> to quit---