I've been using the macports version of dovecot, which is 1.1.11, on MacOS 10.5.6
$ /opt/local/sbin/dovecot --exec-mail imap Fatal: kevent(EV_ADD, 0) failed: Operation not supported
This version is configured --with-ioloop=kqueue
The problem seems to be known, if not understood: http://lists.apple.com/archives/Darwin-userlevel/2008/Dec/msg00010.html
However, if I use --with-ioloop=poll, I eventually get
IMAP(dave): [9079]: invalid I/O fd 0, callback 0x9330
(not from the above command; it's a little later when Gnus tries to interact with dovecot through the shell)
I've been unable to build/install any later versions of dovecot on MacOS. autogen.sh fails like this:
...
glibtoolize: putting auxiliary files in .'. glibtoolize: copying file ./ltmain.sh'
glibtoolize: Consider adding AC_CONFIG_MACRO_DIR([m4])' to configure.in and glibtoolize: rerunning glibtoolize, to keep the correct libtool macros in-tree. glibtoolize: Consider adding -I m4' to ACLOCAL_AMFLAGS in Makefile.am.
configure.in:281: installing ./config.guess' configure.in:282: required file ./config.rpath' not found
configure.in:281: installing ./config.sub' configure.in:5: installing ./install-sh'
configure.in:5: installing ./missing' src/auth/Makefile.am: installing ./depcomp'
autoreconf: automake failed with exit status: 1
-- Dave Abrahams BoostPro Computing http://www.boostpro.com