egit rejected non-fast-forward

This might not be the right way to do it but it removes the error message.

  1. Right-click on your project.
  2. Select Team->Synchronize Workspace.
  3. Go through the compare view of each file and then update your local file accordingly.
  4. Then, right-click on the file, click on Marked as Merged.
  5. Back to project view, right-click on your project and select Team->Merge....
  6. Right-click on your project and select Team->Push to Upstream.