### Please describe the problem.

The transferrer crashes after a while due to too many open files

### What steps will reproduce the problem?

Have a huge annex. Connect two local machines, one with the huge annex, the other one without. Let them copy files…

### What version of git-annex are you using? On what operating system?

latest version
git-annex version: 5.20131117-gbd514dc
build flags: Assistant Webapp Pairing Testsuite S3 WebDAV FsEvents XMPP DNS Feeds Quvi TDFA CryptoHash
key/value backends: SHA256E SHA1E SHA512E SHA224E SHA384E SKEIN256E SKEIN512E SHA256 SHA1 SHA512 SHA224 SHA384 SKEIN256 SKEIN512 WORM URL
remote types: git gcrypt S3 bup directory rsync web webdav glacier hook

on Mac OS X 10.9

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log

[2013-11-22 10:49:19 CET] Transferrer: Downloaded oktaeder.png
[2013-11-22 10:49:19 CET] Transferrer: Downloaded oktaeder.png
[2013-11-22 10:49:19 CET] Transferrer: Downloaded oktaeder.png
[2013-11-22 10:49:20 CET] Transferrer: Downloaded klett-cover-neu.jpg
[2013-11-22 10:49:20 CET] Transferrer: Downloaded klett-cover-neu.jpg
[2013-11-22 10:49:20 CET] Transferrer: Downloaded kara-worl..ditor.gif
git-annex: runInteractiveProcess: pipe: Too many open files
Committer crashed: lsof: createProcess: resource exhausted (Too many open files)
[2013-11-22 10:49:20 CET] Committer: warning Committer crashed: lsof: createProcess: resource exhausted (Too many open files)
[2013-11-22 10:49:20 CET] Transferrer: Downloaded kara-worl..ditor.gif
[2013-11-22 10:49:20 CET] Transferrer: Downloaded kara-worl..ditor.gif
[2013-11-22 10:49:20 CET] Transferrer: Downloaded image1.png
[2013-11-22 10:49:21 CET] Transferrer: Downloaded image1.png
[2013-11-22 10:49:21 CET] Transferrer: Downloaded image.png
[2013-11-22 10:49:21 CET] Transferrer: Downloaded image.png
[2013-11-22 10:49:21 CET] Transferrer: Downloaded ikoseder.png
[2013-11-22 10:49:21 CET] Transferrer: Downloaded ikoseder.png
[2013-11-22 10:49:22 CET] Transferrer: Downloaded ikoseder.png
[2013-11-22 10:49:22 CET] Transferrer: Downloaded ikosaeder.jpg
git-annex: runInteractiveProcess: pipe: Too many open files
ok
(Recording state in git...)
git-annex: socket: resource exhausted (Too many open files)
[2013-11-22 10:49:22 CET] Transferrer: Downloaded ikosaeder.jpg
Transferrer crashed: getCurrentDirectory: resource exhausted (Too many open files)
[2013-11-22 10:49:22 CET] Transferrer: warning Transferrer crashed: getCurrentDirectory: resource exhausted (Too many open files)
git-annex: runInteractiveProcess: pipe: Too many open files
git-annex: runInteractiveProcess: pipe: Too many open files

# End of transcript or log.
"""]]
