Enable Core Dumps

Add this to httpd.conf:

CoreDumpDirectory /tmp/mycoredump

Create the directory, set permissions, and restart Apache:

mkdir /etc/httpd/mycoredump
chown apache: /etc/httpd/mycoredump
systemctl restart httpd

Read the core dump:

gdb /sbin/httpd /etc/httpd/mycoredump/coredumpfilename
# (for backtrace) to get a stack trace from the time of the crash
bt full

CoreDumpDirectory processing only occurs for a select set of fatal signals: SIGFPE, SIGILL, SIGABORT, SIGSEGV, and SIGBUS.
To test and generate a core dump for Apache do the following:

# send SIGILL, Illegal instruction (ANSI) to Apache:
kill -s 4 pidofapache