BUG: Regression from v2.1.4 to v2.2.0 when querying pd.NaT/timestamp comparison

[TheDurableDane]

Pandas version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

import pandas as pd

now = pd.Timestamp.utcnow()
df = pd.DataFrame({'a': [None, None]})
df.loc[:, 'a'] = pd.to_datetime(df.loc[:, 'a'], utc=True)
df2 = df.query('a > @now')

Issue Description

The final line of the reproducible example throws an error:

TypeError: Invalid comparison between dtype=datetime64[ns] and Timestamp

in v2.2.0 but not in v2.1.4. I suspect this is not intended behavior. If not, I would like to know why the behavior has changed and how to fix my code.

Expected Behavior

The expected behavior is as in v2.1.4 which results in df2 being an empty dataframe.

Installed Versions

INSTALLED VERSIONS

commit : fd3f571
python : 3.10.12.final.0
python-bits : 64
OS : Linux
OS-release : 6.5.0-14-generic
Version : #14~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon Nov 20 18:15:30 UTC 2
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8

pandas : 2.2.0
numpy : 1.26.3
pytz : 2023.3.post1
dateutil : 2.8.2
setuptools : 69.0.3
pip : 22.0.4
Cython : None
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 3.1.3
IPython : None
pandas_datareader : None
adbc-driver-postgresql: None
adbc-driver-sqlite : None
bs4 : None
bottleneck : None
dataframe-api-compat : None
fastparquet : None
fsspec : None
gcsfs : None
matplotlib : 3.8.2
numba : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pyreadstat : None
python-calamine : None
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
zstandard : None
tzdata : 2023.4
qtpy : None
pyqt5 : None

[rhshadrach]

Thanks for the report, confirmed on main and that df["a"] > now is successful. Further investigations and PRs to fix are welcome!

[rhshadrach]

Result of a git bisect

commit e0f3a188f9c0b5c334dffe11a5a3ab47fe0870b4
Author: Patrick Hoefler
Date:   Mon Dec 4 11:55:56 2023 +0100

    CoW: Fix warnings for eval (#56170)
    
    Co-authored-by: Joris Van den Bossche

 pandas/core/computation/eval.py       | 15 ++++-----------
 pandas/core/generic.py                |  7 ++++++-
 pandas/tests/computation/test_eval.py | 12 ++++--------
 3 files changed, 14 insertions(+), 20 deletions(-)

cc @phofl @jorisvandenbossche