Comment 3 for bug 1226282

Just found following things in the buildlogs:

amd64 https://launchpadlibrarian.net/145850380/buildlog_ubuntu-saucy-amd64.mupen64plus-core_2.0-2_UPLOADING.txt.gz

Searching for duplicated docs in dependency libmupen64plus2...
  symlinking changelog.Debian.gz in libmupen64plus2-dbg to file in libmupen64plus2
pkgstripfiles: PNG optimization for package libmupen64plus2-dbg took 0 s

i386 https://launchpadlibrarian.net/145850640/buildlog_ubuntu-saucy-i386.mupen64plus-core_2.0-2_UPLOADING.txt.gz

Searching for duplicated docs in dependency mupen64plus-data...
  symlinking changelog.Debian.gz in libmupen64plus2 to file in mupen64plus-data
pkgstripfiles: PNG optimization for package libmupen64plus2 took 0 s
dpkg-deb: warning: 'debian/libmupen64plus2/DEBIAN/control' contains user-defined field 'Original-Maintainer'
dpkg-deb: warning: ignoring 1 warning about the control file(s)

dpkg-deb: building package `libmupen64plus2' in `../libmupen64plus2_2.0-2_i386.deb'.
INFO: pkgstriptranslations version 118
pkgstriptranslations: processing libmupen64plus2-dbg (in debian/libmupen64plus2-dbg); do_strip: , oemstrip:
pkgmaintainermangler: Maintainer field overridden to "Ubuntu Developers <email address hidden>"
pkgstripfiles: processing control file: debian/libmupen64plus2-dbg/DEBIAN/control, package libmupen64plus2-dbg, directory debian/libmupen64plus2-dbg
.. removing usr/share/doc/libmupen64plus2-dbg/changelog.gz
Searching for duplicated docs in dependency libmupen64plus2...
  symlinking changelog.Debian.gz in libmupen64plus2-dbg to file in mupen64plus-data
pkgstripfiles: PNG optimization for package libmupen64plus2-dbg took 0 s

So it is definitely a Ubuntu specific bug which seems to be caused by pkgbinarymangler.