pkgbinarymangler looks to have not propogated error from dpkg-deb

A build succeeded and failed to upload with:

  INFO Upload was rejected:
  INFO linux-image-unsigned-5.8.0-18-generic-dbgsym_5.8.0-18.19~20.04.3_amd64.ddeb: extracting control file raised <type 'exceptions.SystemError'>: E:Archive is too short. giving up.

Looking at the full log the package build ran out of disk space:

dh_builddeb -plinux-image-unsigned-5.8.0-18-generic-dbgsym
INFO: pkgstriptranslations version 144
pkgstriptranslations: processing linux-image-unsigned-5.8.0-18-generic-dbgsym (in debian/linux-image-unsigned-5.8.0-18-generic-dbgsym); do_strip: , oemstrip:
pkgmaintainermangler: Not overriding Maintainer for domain lists.ubuntu.com
pkgstripfiles: processing control file: debian/linux-image-unsigned-5.8.0-18-generic-dbgsym/DEBIAN/control, package linux-image-unsigned-5.8.0-18-generic-dbgsym, directory debian/linux-image-unsigned-5.8.0-18-generic-dbgsym
dpkg-deb: building package 'linux-image-unsigned-5.8.0-18-generic-dbgsym' in '../linux-image-unsigned-5.8.0-18-generic-dbgsym_5.8.0-18.19~20.04.3_amd64.deb'.
dpkg-deb: error: cannot append ar member file (data.tar.xz) to '../linux-image-unsigned-5.8.0-18-generic-dbgsym_5.8.0-18.19~20.04.3_amd64.deb': failed to write (No space left on device)
dh_builddeb.pkgbinarymangler: error: dpkg-deb --build debian/linux-image-unsigned-5.8.0-18-generic-dbgsym .. returned exit code 2
dh_builddeb.pkgbinarymangler: error: Aborting due to earlier error
# Hokay...here's where we do a little twiddling...

The build seems have continued without noticing. The dh_builddeb is called from a debian/rules fragment in a manner tested to detect the error if any was present.