Fix a scoping issue in _get_irreducible_buses_due_to_dlrs

[odow]

This threw me for a loop. I'm using

import Dates
import HiGHS
import PowerOperationsModels as POM
import PowerSystems as PSY
sys = PSY.System(joinpath(@__DIR__, "performance", "CATS_Sienna.json"))
PSY.transform_single_time_series!(sys, Dates.Hour(1), Dates.Hour(1))
template = POM.OperationsProblemTemplate(
    POM.NetworkModel(
        POM.PTDFPowerModel;
        use_slacks = true,
        duals = [POM.CopperPlateBalanceConstraint],
    ),
);
POM.set_device_model!(template, PSY.ThermalStandard, POM.ThermalBasicUnitCommitment)
POM.set_device_model!(template, PSY.RenewableDispatch, POM.RenewableFullDispatch)
POM.set_device_model!(template, PSY.HydroDispatch, POM.HydroDispatchRunOfRiver)
POM.set_device_model!(template, PSY.PowerLoad, POM.StaticPowerLoad)
POM.set_device_model!(template, PSY.Line, POM.StaticBranch)
POM.set_device_model!(template, PSY.Transformer2W, POM.StaticBranch)
model = POM.DecisionModel(
    template,
    sys;
    name = "CATS_UC2",
    optimizer = HiGHS.Optimizer,
);
POM.build!(model; output_dir = mktempdir(; cleanup = true))

as a script. And I had it working. Then restarted Julia and had a cryptic error message about a missing symbol "PowerSystems.Line".

The issue is that in the guts of set_device_model! we call nameof(D) to set the key:

https://github.com/Sienna-Platform/InfrastructureOptimizationModels.jl/blob/9ccee6240f9b07ee16bf5a23b144e2a9e4fc4459/src/core/device_model.jl#L112-L116

but in POM we use Symbol(D). These differ depending on whether D is in the current scope:

julia> import PowerSystems as PSY

julia> nameof(PSY.Line)
:Line

julia> Symbol(PSY.Line)
Symbol("PowerSystems.Line")

julia> using PowerSystems

julia> Symbol(PSY.Line)
:Line

julia> Symbol(PSY.Line)
:Line

I must have had using PowerSystems in the first REPL and not the second.

[github-actions]

Performance Results

Version	Precompile Time
Main	2.82504863
This Branch	2.801345689

Version	Build Time
Main-Build Time Precompile	97.367770511
Main-Build Time Postcompile	14.674480712
This Branch-Build Time Precompile	96.421118763
This Branch-Build Time Postcompile	14.640758201

Version	Solve Time
Main-Solve Time Precompile	391.356066522
Main-Solve Time Postcompile	359.336073663
This Branch-Solve Time Precompile	165.101334033
This Branch-Solve Time Postcompile	133.026968389

[luke-kiernan]

This comes up in other spots too. (IS's test_printing.jl used to compare with ==, but then it started erroring due to InfrastructureSystems.Foo vs Foo, so I changed it to occursin.) It'd be great to have a comprehensive approach for this.

[odow]

It'd be great to have a comprehensive approach for this.

The "correct" approach is to use the actual data types as keys, rather than converting them to some sort of Symbol.

The issue is that it's really hard to detect and fix these scoping issues because they depend on package imports, and the tests just bring everything into scope with using.