The error message when adding the two components with identical label is not helpful

[fwitte]

It would be nice, if there would be an exact error message instead of this:

[fwitte]

es = EnergySystem(timeindex=solph.create_time_index(2024, number=2))
bus_heat = Bus("heat")
bus_electricity = Bus("electricity")

converter1 = Converter(
    label="converter",
    inputs={bus_electricity: Flow()},
    outputs={bus_heat: Flow(nominal_value=1)}
)

converter2 = Converter(
    label="converter",
    inputs={bus_electricity: Flow()},
    outputs={bus_heat: Flow(nominal_value=1)}
)

es.add(bus_heat, bus_electricity, converter1, converter2)

[p-snft]

This should/might be fixed by #1139.

[fwitte]

Thank you!

There is one more: In case you have not added a component to the EnergySystem it is similarly not helpful. It is nice to have that raising an error (to not accidentally forget about a part of the system), but it should point the user towards that.

[p-snft]

I have to correct myself: After merging #1139, it will fail earlier, but not directly on the error.

Adding two Nodes with the same label could be caught in oemof.network. However, I don't see how having two Flows between the same Nodes could be addressed as a possible error. (In particular, overwriting is a possibility in both cases.) Also, not adding a Node is hard to detect.