Comment 8 for bug 927993

From a strace log:

[pid 19148] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--status-fd", "30", "--unpack", "--auto-deconfigure", "/var/cache/apt/archives/initscripts_2.88dsf-13.10ubuntu10_amd64.deb"], [/* 31 vars */]) = 0^M
...
[pid 19197] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--status-fd", "30", "--configure", "dpkg"], [/* 31 vars */]) = 0^M
dpkg: error processing dpkg (--configure):^M^M
 package dpkg is already installed and configured^M^M

The last few lines with only --unpack and --configure:

[pid 18764] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--st
atus-fd", "30", "--unpack", "--auto-deconfigure", "/var/cache/apt/archives/libpo
lkit-gobject-1-0_0.104-1_amd64.deb", "/var/cache/apt/archives/wpasupplicant_0.7.
3-6ubuntu1_amd64.deb", "/var/cache/apt/archives/isc-dhcp-common_4.1.ESV-R4-0ubun
tu1_amd64.deb", "/var/cache/apt/archives/ifupdown_0.7~beta2ubuntu6_amd64.deb", "
/var/cache/apt/archives/network-manager-gnome_0.9.2.0+git.20120126t000800.515195
9-0ubuntu4_amd64.deb", "/var/cache/apt/archives/network-manager-pptp_0.9.2.0-1ub
untu1_amd64.deb", "/var/cache/apt/archives/network-manager_0.9.2.0+git2012021618
54.8572ecf-0ubuntu4_amd64.deb", "/var/cache/apt/archives/ppp_2.4.5-5ubuntu1_amd6
4.deb"], [/* 31 vars */]) = 0
[pid 19084] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--st
atus-fd", "30", "--configure", "libdbus-glib-1-2", "libnl-3-200", "libnl-genl-3-
200", "libnl-route-3-200"], [/* 31 vars */]) = 0
[pid 19110] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--st
atus-fd", "30", "--unpack", "--auto-deconfigure", "/var/cache/apt/archives/libns
pr4_4.8.9-1ubuntu2_amd64.deb"], [/* 31 vars */]) = 0
[pid 19120] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--st
atus-fd", "30", "--configure", "libnspr4", "libnss3", "libnm-util2", "libnm-glib
4", "libpolkit-gobject-1-0"], [/* 31 vars */]) = 0
[pid 19148] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--st
atus-fd", "30", "--unpack", "--auto-deconfigure", "/var/cache/apt/archives/inits
cripts_2.88dsf-13.10ubuntu10_amd64.deb"], [/* 31 vars */]) = 0
[pid 19197] execve("/usr/bin/dpkg", ["/usr/bin/dpkg", "--force-overwrite", "--st
atus-fd", "30", "--configure", "dpkg"], [/* 31 vars */]) = 0

No sign of dpkg itself being unpacked before the configure *but* its clearly there in the Debug::pkgDPkgPM=1 output.