Please describe the problem.

git annex merge goes out of memory on a large repo.

What steps will reproduce the problem?

$ git annex merge
merge git-annex git-annex: out of memory (requested 1048576 bytes)

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

git-annex version: 4.20130827
build flags: Assistant Webapp Pairing Testsuite S3 WebDAV Inotify DBus XMPP DNS

On debian wheezy i386

Please provide any additional information below.

The repository contains a lot of files:

$ cd .git/objects
$ find . -type f | wc -l