Error in prepare_network from add_dynamic_emission_prices

[MaxBrehm]

I encountered an issue when enableing:

costs:
  emission_prices:
    enable: false 
    co2_monthly_prices: true

in my config.

localrule prepare_network:
    input: resources/max-2/test_01/networks/base_s_100_elec.nc, resources/max-2/test_01/costs_2030.csv
    output: resources/max-2/test_01/networks/base_s_100_elec_Ep.nc
    log: logs/max-2/test_01/prepare_network_base_s_100_elec_Ep.log
    jobid: 2
    benchmark: benchmarks/max-2/test_01/prepare_network_base_s_100_elec_Ep
    reason: Missing output files: resources/max-2/test_01/networks/base_s_100_elec_Ep.nc; Input files updated by another job: resources/max-2/test_01/networks/base_s_100_elec.nc, resources/max-2/test_01/costs_2030.csv
    wildcards: clusters=100, opts=Ep
    resources: tmpdir=/tmp, mem_mb=4000, mem_mib=3815

INFO:pypsa.io:Imported network base_s_100_elec.nc has buses, carriers, generators, lines, loads, storage_units
INFO:__main__:N-1 security margin of lines set to 0.7
INFO:__main__:Resampling the network to 1H
/home/maxb/Dokumente/Masterarbeit/pypsa-eur/pypsa-eur/.snakemake/scripts/tmprw7f0a8c.prepare_network.py:192: FutureWarning: 'H' is deprecated and will be removed in a future version, please use 'h' instead.
  snapshot_weightings = n.snapshot_weightings.resample(offset).sum()
/home/maxb/Dokumente/Masterarbeit/pypsa-eur/pypsa-eur/.snakemake/scripts/tmprw7f0a8c.prepare_network.py:203: FutureWarning: 'H' is deprecated and will be removed in a future version, please use 'h' instead.
  pnl[k] = df.resample(offset).mean()
INFO:__main__:Setting time dependent emission prices according spot market price
ERROR:root:Uncaught exception
Traceback (most recent call last):
  File "/home/maxb/Dokumente/Masterarbeit/pypsa-eur/pypsa-eur/.snakemake/scripts/tmprw7f0a8c.prepare_network.py", line 342, in <module>
    add_dynamic_emission_prices(n)
  File "/home/maxb/Dokumente/Masterarbeit/pypsa-eur/pypsa-eur/.snakemake/scripts/tmprw7f0a8c.prepare_network.py", line 126, in add_dynamic_emission_prices
    co2_price = pd.read_csv(snakemake.input.co2_price, index_col=0, parse_dates=True)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/maxb/miniconda3/envs/pypsa-eur/lib/python3.12/site-packages/pandas/io/parsers/readers.py", line 1026, in read_csv
    return _read(filepath_or_buffer, kwds)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/maxb/miniconda3/envs/pypsa-eur/lib/python3.12/site-packages/pandas/io/parsers/readers.py", line 620, in _read
    parser = TextFileReader(filepath_or_buffer, **kwds)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/maxb/miniconda3/envs/pypsa-eur/lib/python3.12/site-packages/pandas/io/parsers/readers.py", line 1620, in __init__
    self._engine = self._make_engine(f, self.engine)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/maxb/miniconda3/envs/pypsa-eur/lib/python3.12/site-packages/pandas/io/parsers/readers.py", line 1895, in _make_engine
    raise ValueError(msg)
ValueError: Invalid file path or buffer object type: <class 'snakemake.io.Namedlist'>