### Please describe the problem.
When attempting to add a file listed in .gitignore, git annex exits silently. I would expect to see an error message a la plain git: "The following paths are ignored by one of your .gitignore files: _that file_"

### What steps will reproduce the problem?
1. Add a file to .gitignore
2. git annex add _that file_

### What version of git-annex are you using? On what operating system?
git-annex version: 6.20160613
build flags: Assistant Webapp Pairing Testsuite S3(multipartupload)(storageclasses) WebDAV FsEvents XMPP ConcurrentOutput TorrentParser MagicMime Feeds Quvi
key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_224 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 SHA1E SHA1 MD5E MD5 WORM URL
remote types: git gcrypt S3 bup directory rsync web bittorrent webdav tahoe glacier ddar hook external
local repository version: 5
supported repository versions: 5 6
upgrade supported from repository versions: 0 1 2 3 4 5
operating system: darwin x86_64


### 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


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

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)


