Fatal crash after deep-copy of data outside context manager

What happened?

If I want to open a the same file to read data from it the interpreter crashes. Probably other situations where the code would crash as well.

The bug seems to originate from the fact the copy(deep=True) is executed outside the context manager. If the code is move into the context manager then it runs fine.

What did you expect to happen?

It should either just work,
or an exception should be thrown when making a deep-copy outside the context (if that is indeed the cause).

Minimal Complete Verifiable Example

import xarray as xr

filename = 'dummy.nc'

with xr.open_dataarray(filename, group="damping", engine="netcdf4") as ds:
    damping = ds

# make a deep-copy and interpolate the copy (outside context manager)
new_damping = ds.copy(deep=True)
new_damping = new_damping.interp(omega=[0.1, 0.2, 0.3], method="linear")

# opening "damping" again - ok
with xr.open_dataarray(filename, group="damping", engine="netcdf4") as ds:
    pass


print('opening "mass" again - crashes')
with xr.open_dataarray(filename, group="mass", engine="netcdf4") as ds:
    pass

MVCE confirmation

• Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
• 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 or Binder notebook, 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 xarray and its dependencies.

Relevant log output

Process finished with exit code -1073741819 (0xC0000005)

Anything else we need to know?

No response

Environment

Start by running the provided MVCE with xarray's netCDF4 engine on Windows and confirm the access-violation crash after deep-copying outside the context manager. Trace the deep-copy and resource-lifecycle paths involved in open_dataarray, then add a regression test or behavior check showing that reopening the file either succeeds or raises a Python exception instead of crashing.