### Please describe the problem.

Adding my 43GB Music Studio folder with 85K files causes out of memory or file not found errors. I subsequently tried on a very small folder but it still fails. --debug gives nothing useful that I can see.


### What steps will reproduce the problem?

cd Studio
git init
git annex init
git annex add


### What version of git-annex are you using? On what operating system?
git-annex version: 5.20140613-g5587055
build flags: Assistant Webapp Webapp-secure Pairing Testsuite S3 WebDAV 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 tahoe glacier ddar hook external
local repository version: 5
supported repository version: 5
upgrade supported from repository versions: 2 3 4

Running on Windows 8.1 x64, Git Bash, Direct Mode, WORM backend

### 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

fatal: Out of memory? mmap failed: No such file or directory
git-annex: add: 8562 failed

Phil@DESKTOP /c/Studio (annex/direct/master)
$ git annex add audacity
fatal: Out of memory? mmap failed: No such file or directory
(Recording state in git...)


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

[[!meta title="msysgit failure on Windows: mmap failed: No such file or directory "]]