block packages failing to build and depending on ruby1.8 for trusty

$ reverse-depends -b src:ruby-pkg-tools
Reverse-Build-Depends
=====================
* libnet-netrc-ruby (for ruby-pkg-tools)
* libzip-ruby (for ruby-pkg-tools)
* right-aws (for ruby-pkg-tools)

ruby-pkg-tools is removed in Debian testing/unstable

right-aws is Ubuntu only, proposing to remove it
libzip-ruby and libnet-netrc-ruby are removed in Debian testing/unstable

This bug was fixed in the package dhelp - 0.6.21+nmu6ubuntu1

---------------
dhelp (0.6.21+nmu6ubuntu1) vivid; urgency=medium

  * Merge from Debian unstable. (LP: #1283061) Remaining changes:
    - lib/dhelp.rb: Exit and return zero code if bdb isn't available; this
      usually indicates that dhelp is not configured yet.

dhelp (0.6.21+nmu6) unstable; urgency=medium

  * Non-maintainer upload.
  * Fix "Fails to build the index when invalid UTF-8 is met":
    apply patch from Daniel Getz:
    + Load files as UTF-8, regardless of $LANG
    (Closes: #768127)

dhelp (0.6.21+nmu5) unstable; urgency=medium

  * Non-maintainer upload.
  * Update French program translation (Closes: #684664)
  * Update Russian program translation (Closes: #688667)
  * Update German program translation (Closes: #689063)
  * Add Danish program translation (Closes: #689644)
  * Add Italian program translation (Closes: #689920)
  * Add Portugese program translation (Closes: #724781)

dhelp (0.6.21+nmu4) unstable; urgency=low

  * Non-maintainer upload.
  * Add support for newer ruby versions (Closes: #734523, #732916)
  * Cache 'Dpkg.status' calls to not affect performance on every system
      upgrade (Closes: #712621)
  * Handle correctly arguments passed to '-a' and '-d' options
  * Fix error when 'dhelp_parse' is called without arguments
  * Fix Ruby warnings
  * Change the encoding of Ruby files to UTF-8
 -- Jackson Doak <email address hidden> Mon, 05 Jan 2015 18:13:27 +1100