[git] fatal: git-write-tree: error building trees

I did a git pull from a shared git repository, but something went really wrong, after I tried a git revert. Here is the situation now:

$ git stash
Source/MediaStorageAndFileFormat/gdcmImageCodec.cxx: needs merge
Source/MediaStorageAndFileFormat/gdcmJPEGLSCodec.cxx: needs merge
Source/MediaStorageAndFileFormat/gdcmPNMCodec.cxx: needs merge
Testing/Source/DataStructureAndEncodingDefinition/Cxx/TestDS.cxx: needs merge
Utilities/socketxx/socket++/sockstream.cpp: needs merge
Source/MediaStorageAndFileFormat/gdcmImageCodec.cxx: needs merge
Source/MediaStorageAndFileFormat/gdcmJPEGLSCodec.cxx: needs merge
Source/MediaStorageAndFileFormat/gdcmPNMCodec.cxx: needs merge
Testing/Source/DataStructureAndEncodingDefinition/Cxx/TestDS.cxx: needs merge
Utilities/socketxx/socket++/sockstream.cpp: needs merge
Source/MediaStorageAndFileFormat/gdcmImageCodec.cxx: unmerged (2aafac967c35fa4e77c3086b83a3c102939ad168)
Source/MediaStorageAndFileFormat/gdcmImageCodec.cxx: unmerged (78cc95e8bae85bf8345a7793676e878e83df167b)
Source/MediaStorageAndFileFormat/gdcmImageCodec.cxx: unmerged (2524db713fbde0d7ebd86bfe2afc4b4d7d48db33)
Source/MediaStorageAndFileFormat/gdcmJPEGLSCodec.cxx: unmerged (4bb4ba78973091eaa854b03c6ce24e8f4af9e7cc)
Source/MediaStorageAndFileFormat/gdcmJPEGLSCodec.cxx: unmerged (ad0982b8b8b4c4fef23e69bbb639ca6d0cd98dd8)
Source/MediaStorageAndFileFormat/gdcmJPEGLSCodec.cxx: unmerged (4868371b7218c6e007fb6c582ad4ab226167a80a)
Source/MediaStorageAndFileFormat/gdcmPNMCodec.cxx: unmerged (f7a1b386b5b13b8fa8b6a31ce1258d2d5e5b13c5)
Source/MediaStorageAndFileFormat/gdcmPNMCodec.cxx: unmerged (6ce299c416fbb3bb60e11ef1e54962ffd3449a4c)
Source/MediaStorageAndFileFormat/gdcmPNMCodec.cxx: unmerged (75c8043a60a56a1130a34cdbd91d130bc9343c1c)
Testing/Source/DataStructureAndEncodingDefinition/Cxx/TestDS.cxx: unmerged (79c2843f2649ea9c87fa57662dafd899a5fa39ee)
...
fatal: git-write-tree: error building trees
Cannot save the current index state

Is there a way to reset all that ?

Thanks

This happened for me when I was trying to stash my changes, but then my changes had conflicts with my branch's current state.

So I did git reset --mixed and then resolved the git conflict and stashed again.

I used:

 git reset --hard

I lost some changes, but this is ok.

maybe there are some unmerged paths in your git repository that you have to resolve before stashing.

To follow up on malat's response, you can avoid losing changes by creating a patch and reapply it at a later time.

git diff --no-prefix > patch.txt
patch -p0 < patch.txt

Store your patch outside the repository folder for safety.

This worked for me:

Do

$ git status

And check if you have Unmerged paths

# Unmerged paths:
#   (use "git reset HEAD <file>..." to unstage)
#   (use "git add <file>..." to mark resolution)
#
#   both modified:      app/assets/images/logo.png
#   both modified:      app/models/laundry.rb

Fix them with git add to each of them and try git stash again.

git add app/assets/images/logo.png