Incorrect error line number

[ike709]

Compile this commit of Daedalus: https://github.com/DaedalusDock/daedalusdock/blob/15593f1af3c7ded8de8f8e4bd30ac39a1cd592af

Get this error: Error OD0500 at code/modules/reagents/chemistry/machinery/chem_heater.dm:447:15: Expected a constant

But if you breakpoint debug it the _proc is /obj/machinery/chem_heater/proc/get_purity_color(datum/equilibrium/equilibrium) and the true error location is about 30 lines below the error message's reported line number.