DVC .git folder growing

The issue occurs when passing nested data as stage dependency.

In my case, a foreach preprocessing stage recreates directories structure from data/raw in data/interim . The latter is added as a dependency of train stage. Running an experiment leads to .git catalog growing approximately the size of data/interim (with object packs from this folder), and if the data is large - quite a long wait for Updating lock file 'dvc.lock' at the end.

Input data:

data
└───raw
    ├───dirA
    │       file0.txt
    │       file1.txt
    │
    └───dirB
            file0.txt
            file1.txt

Stages:

                +--------------+
                | data\raw.dvc |
                +--------------+
                **            **
              **                **
            **                    **
+-----------------+         +-----------------+
| preprocess@dirA |         | preprocess@dirB |
+-----------------+         +-----------------+
                **            **
                  **        **
                    **    **
                   +-------+
                   | train |
                   +-------+

To reproduce:

1. Create data : python create_data.py (~20 MB)
2. Check .git folder size (small)
3. (optional) Run just the preprocessing stage: dvc exp run -fs preprocess. Check .git folder size (small)
4. Run an experiment dvc exp run -f Check .git folder size (~15 MB)

Tested with dvc 2.52.0 (Windows).

To clean .git folder:

run ./clean.bat