Debugging with Qemu

> Get this KVM qcow2 image

KVM = Kernel Virtual Machine based on wp:QEMU (https://QEMU.org). File is an wp:Xz-compressed (like 7-zip; only GPL) "debug-crash.qcow"

So, I installed QEMU + dependencies

> Please show the commands you use to start via libvirt with this XML.

The xml had /usr/bin/kvm-spice in it as the emulator; so I searched dpkg -S /usr/bin/kvm-spice which turns out to be qemu-kvm (that I already have installed). So I assume that I'll need to run qemu-kvm. So then I researched how to start a qemu-kvm session/machine, using libvirt, and given an XML manifest / configuration file.

To login use
- User: ubuntu
- Password: ubuntu
- SSH server runs by default and guest does dhcp (or use the serial console)
In that image clarify the following things:
- Apache is not starting, why?
- What is going on with /var/crash/_usr_sbin_postconf.1000.crash (use debug
symbols and apport-retrace / apport-unpack to get started)
Makefile Weirdness
It was determined that a certain linker flag was causing problems in the build of a package, so
a change was added to debian/rules to remove that flag:
override_dh_auto_build:
CFLAGS="$(CFLAGS) $(CPPFLAGS)" \
LDFLAGS="$(dpkg-buildflags --get LDFLAGS \
| sed -e 's/-Wl,-Bsymbolic-functions//')" \
dh_auto_build
The flag was removed from LDFLAGS via a simple sed expression. It turns out this change
actually made LDFLAGS empty. Why?