I added some binary files to a git repo on Ubuntu 14.04 linux, pushed those files to a GitHub remote then pulled them to existing clones on OS X El Capitan and Windows 10. git status on OS X and Windows shows some of these files as modified even though they have not been touched. It continues to shown them as changed even after git reset --hard and git checkout.
Note, I am using Git LFS (Large File Storage) with these files.
Here is the output from git diff on OS X where only 1 file shows as modified:
Marks-MacBook:KTX mark$ git diff other_lib/linux/Release-x64/libSDL2main.a
diff --git a/other_lib/linux/Release-x64/libSDL2main.a b/other_lib/linux/Release-x64/libSDL2main.a
index 4202f6f..2797199 100644
Binary files a/other_lib/linux/Release-x64/libSDL2main.a and b/other_lib/linux/Release-x64/libSDL2main.a differ
and
Marks-MacBook:KTX mark$ git diff --raw other_lib/linux/Release-x64/libSDL2main.a
:100644 100644 4202f6f... 0000000... M  other_lib/linux/Release-x64/libSDL2main.a
The files are marked -text in .gitattributes so there should not be any issues with EOL markers. What else could cause the different sha1 results and git diff to report the binary files differ?
I added a diff=bin to .gitattributes for *.a files where bin uses textconv = hexdump -v -C. After this git diff reports no differences but git status still shows the files as modified.
As an additional test, I copied the original .a file from linux to OS X and used diff to compare it with the copy in my git working tree. They are identical. git status on the linux repo clone reports the working tree file, that I copied, is unmodified. 
Any suggestions?
The following is no longer true; the repo has been fixed as described in my answer.
You can try for yourselves. The repo & branch is on GitHub at https://github.com/KhronosGroup/KTX/tree/incoming. The file showing the problem on OS X is other_lib/linux/Release-x64/libSDL2main.a. There is no problem with any of the other .a files under other_lib/linux.
On Windows a few more files are shown as modified including some that are symbolic links on Linux. I want to concentrate on the OS X case for now since it is simpler.
 
    