We recently received this bug report at Debian,
Note that debian ships hunspell 1.3.2.
This seems related to a problem with init string in pipe mode. When looking at hunspell.cxx code I noticed another potencial problem for Emacs. Here goes a summary of noticed problems,
* The string is gettextized. Emacs (and may be others) heavily rely in
English format to get info like spellchecker version. This may not work
with translated string.
* In pipe mode hunspell.cxx outputs version string as soon as it detects
the -a switch, even if hunspell is not properly started because of
This behavior is different from what ispell and aspell do and confuses
Emacs (output that string only when hunspell has properly started),
causing Emacs hang if a missing dictionary is selected.
Emacs waits for more info after that string is received.
This is whan seems to trigger http://bugs.debian.org/690318.
I have been playing with this and attach a patch with the changes I did in my tests. Patched hunspell seems to work well and fix that problem, but is minimally tested with Emacs under normal use. Not sure if may affect other areas.