Have you tried compiling ftp://ftp.gnupg.org/gcrypt/pinentry/pinentry-0.8.4.tar.bz2?
Probably would require configure settings such as --enable-pinentry-qt4=no --enable-pinentry-qt4-clipboard=no --enable-pinentry-curses --enable-embedded=no --enable-pinentry-qt=no --enable-pinentry-gtk2=no --enable-pinentry-gtk=no --enable-pinentry-tty --disable-gtktest