$ ./test.sh 
init git repo
Initialized empty Git repository in /tmp/tmp_repo/.git/
add commit to original repo
[master (root-commit) 4eff82a] add_foo_file
 0 files changed
 create mode 100644 foo
clone repo
Cloning into 'tmp_repo_clone'...
done.
checkout and make left branch
Branch left set up to track remote branch master from origin.
Switched to a new branch 'left'
[left 9065254] conflict_left
 2 files changed, 2 insertions(+)
 create mode 100644 conflict_file
 create mode 100644 left_only_file
checkout and make right branch
Branch right set up to track remote branch master from origin.
Switched to a new branch 'right'
[right 6834ae6] conflict_right
 2 files changed, 2 insertions(+)
 create mode 100644 conflict_file
 create mode 100644 right_only_file
merge left
Auto-merging conflict_file
CONFLICT (add/add): Merge conflict in conflict_file
Automatic merge failed; fix conflicts and then commit the result.
try and make diff
done