Double upgrading a repo object causes a panic

[ianhi]

What happened?

If you call upgrade repo on the same repo object multiple times you cause a panic.

➜  version-compat-tests git:(ian/v1-v2-regression-tests) ✗ uv run python scripts/double_upgrade.py

thread '<unnamed>' (5051741) panicked at /Users/runner/work/icechunk/icechunk/icechunk/src/format/repo_info.rs:168:9:
assertion failed: main_found
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Traceback (most recent call last):
  File "/Users/ian/Documents/dev/icechunk/version-compat-tests/scripts/double_upgrade.py", line 28, in <module>
    main()
    ~~~~^^
  File "/Users/ian/Documents/dev/icechunk/version-compat-tests/scripts/double_upgrade.py", line 24, in main
    icechunk.upgrade_icechunk_repository(repo, dry_run=False)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ian/Documents/dev/icechunk/version-compat-tests/.venv/lib/python3.14/site-packages/icechunk/__init__.py", line 267, in upgrade_icechunk_repository
    _upgrade_icechunk_repository(
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        repo._repository, dry_run=dry_run, delete_unused_v1_files=delete_unused_v1_files
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
pyo3_runtime.PanicException: assertion failed: main_found

What did you expect to happen?

no panics!

Minimal Complete Verifiable Example

# /// script
# requires-python = ">=3.11"
# dependencies = [
#   "icechunk<2",
#   "zarr",
# ]
#
# [[tool.uv.index]]
# name = "scientific-python-nightly-wheels"
# url = "https://pypi.anaconda.org/scientific-python-nightly-wheels/simple/"
#
# [tool.uv.sources]
# icechunk = { index = "scientific-python-nightly-wheels" }
# zarr = { index = "scientific-python-nightly-wheels" }
#
# [tool.uv]
# prerelease = "allow"
# ///
#
# This script automatically imports the development branch of icechunk to check for issues.
# Please delete this header if you have _not_ tested this script with `uv run`!
import tempfile
import icechunk
import zarr


icechunk.set_logs_filter("icechunk::storage::object_store=error")

tmpdir = tempfile.mkdtemp()
storage = icechunk.local_filesystem_storage(tmpdir)

# Create repo with spec_version=1
repo = icechunk.Repository.create(storage, spec_version=1)

# Make initial data and commit
session = repo.writable_session("main")
root = zarr.open_group(session.store, mode="w")
arr = root.create_array("data", shape=(2,), dtype="i4")
arr[:] = [1, 2]
commit1 = session.commit("first commit")

# Upgrade to spec_version=2
icechunk.upgrade_icechunk_repository(repo, dry_run=False)
icechunk.upgrade_icechunk_repository(repo, dry_run=False)

MVCE confirmation

• Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in icechunk.
• Complete example — the example is self-contained, including all data and the text of any traceback.
• Verifiable example — the example copy & pastes into an IPython prompt, returning the result.
• New issue — a search of GitHub Issues suggests this is not a duplicate.
• Recent environment — the issue occurs with the latest version of icechunk and its dependencies.

Relevant log output

Anything else we need to know?

No response

Environment

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