apt-key update is failing if 39 keys in trusted.gpg.d

Debugging the script apt-key I found that the problem is triggered by gpg.

The following command is failing:

cat /tmp/step_data | gpg --yes --ignore-time-conflict --no-options --no-default-keyring --homedir /tmp/tmp.jtTZwIQ6EI --no-auto-check-trustdb --trust-model always --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyring /etc/apt/trusted.gpg.d/andrei-pozolotin-maven3.gpg --keyring /etc/apt/trusted.gpg.d/b-eltzner-qpdfview.gpg --keyring /etc/apt/trusted.gpg.d/boomaga-ppa.gpg --keyring /etc/apt/trusted.gpg.d/cassou-emacs.gpg --keyring /etc/apt/trusted.gpg.d/costamagnagianfranco-virtualbox-ppa.gpg --keyring /etc/apt/trusted.gpg.d/cpug-devs-ppa.gpg --keyring /etc/apt/trusted.gpg.d/debian-archive-squeeze-automatic.gpg --keyring /etc/apt/trusted.gpg.d/debian-archive-squeeze-stable.gpg --keyring /etc/apt/trusted.gpg.d/debian-archive-wheezy-automatic.gpg --keyring /etc/apt/trusted.gpg.d/debian-archive-wheezy-stable.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-backport-games.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-backport-gnome3.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-backport-staging.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-backport.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-edge.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-jail.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-c42-other.gpg --keyring /etc/apt/trusted.gpg.d/dirk-computer42-squid-ssl.gpg --keyring /etc/apt/trusted.gpg.d/dschaerf-myubuntu.gpg --keyring /etc/apt/trusted.gpg.d/gmpc-trunk-mpd-trunk.gpg --keyring /etc/apt/trusted.gpg.d/gnome3-team-gnome3-next.gpg --keyring /etc/apt/trusted.gpg.d/gnome3-team-gnome3-staging.gpg --keyring /etc/apt/trusted.gpg.d/gnome3-team-gnome3.gpg --keyring /etc/apt/trusted.gpg.d/i-nex-development-team-stable.gpg --keyring /etc/apt/trusted.gpg.d/leolik-leolik.gpg --keyring /etc/apt/trusted.gpg.d/libreoffice-libreoffice-4-4.gpg --keyring /etc/apt/trusted.gpg.d/m-ioalex-mp3splt.gpg --keyring /etc/apt/trusted.gpg.d/nemh-gambas3.gpg --keyring /etc/apt/trusted.gpg.d/openjdk-r-ppa.gpg --keyring /etc/apt/trusted.gpg.d/ossug-hychen-ppa.gpg --keyring /etc/apt/trusted.gpg.d/stvs-tomate.gpg --keyring /etc/apt/trusted.gpg.d/torkvemada-torkvemada.gpg --keyring /etc/apt/trusted.gpg.d/transmissionbt-ppa.gpg --keyring /etc/apt/trusted.gpg.d/tualatrix-ppa.gpg --keyring /etc/apt/trusted.gpg.d/videolan-master-daily.gpg --keyring /etc/apt/trusted.gpg.d/videolan-stable-daily.gpg --keyring /etc/apt/trusted.gpg.d/webupd8team-java.gpg --keyring /etc/apt/trusted.gpg.d/webupd8team-nemo.gpg --keyring /etc/apt/trusted.gpg.d/webupd8team-themes.gpg --import

If I reduce the number of keys it works.

The data for this command is attached.