Error while loading conic library format

[georgesms]

I was trying to read some .cbf files using MathOptFormat Using this code:

using MathOptInterface, MathOptFormat, MosekTools

const MOI = MathOptInterface

filename = "instances/10_0_1_w.cbf"

mathoptformat_model = MathOptFormat.CBF.Model()

solver = Mosek.Optimizer()

#user_model = nothing
user_model = MOI.Bridges.full_bridge_optimizer(solver , Float64)

println("check 1")
MOI.read_from_file(mathoptformat_model, filename)
println("check 2")
MOI.copy_to(user_model, mathoptformat_model)
@show user_model
println("check 3")
MOI.optimize!(user_model)
x = MOI.get(user_model, MOI.VariableIndex, "x")
@show x

and got:

ERROR: LoadError: Using bridged variable in `SingleVariable` function.
Stacktrace:
 [1] bridged_function at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Bridges/bridge_optimizer.jl:1229 [inlined]
 [2] add_constraints(::MathOptInterface.Bridges.LazyBridgeOptimizer{MosekModel}, ::Array{MathOptInterface.SingleVariable,1}, ::Array{MathOptInterface.Integer,1}) at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Bridges/bridge_optimizer.jl:1062
 [3] copy_constraints(::MathOptInterface.Bridges.LazyBridgeOptimizer{MosekModel}, ::MathOptFormat.CBF.InnerModel{Float64}, ::MathOptInterface.Utilities.IndexMap, ::Array{MathOptInterface.ConstraintIndex{MathOptInterface.SingleVariable,MathOptInterface.Integer},1}) at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Utilities/copy.jl:228
 [4] pass_constraints(::MathOptInterface.Bridges.LazyBridgeOptimizer{MosekModel}, ::MathOptFormat.CBF.InnerModel{Float64}, ::Bool, ::MathOptInterface.Utilities.IndexMap, ::Array{DataType,1}, ::Array{Array{MathOptInterface.ConstraintIndex{MathOptInterface.SingleVariable,MathOptInterface.Integer},1},1}, ::Array{DataType,1}, ::Array{Array{T,1} where T,1}, ::typeof(MathOptInterface.Utilities.copy_constraints), ::typeof(MathOptInterface.set)) at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Utilities/copy.jl:243
 [5] pass_constraints(::MathOptInterface.Bridges.LazyBridgeOptimizer{MosekModel}, ::MathOptFormat.CBF.InnerModel{Float64}, ::Bool, ::MathOptInterface.Utilities.IndexMap, ::Array{DataType,1}, ::Array{Array{MathOptInterface.ConstraintIndex{MathOptInterface.SingleVariable,MathOptInterface.Integer},1},1}, ::Array{DataType,1}, ::Array{Array{T,1} where T,1}) at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Utilities/copy.jl:240
 [6] default_copy_to(::MathOptInterface.Bridges.LazyBridgeOptimizer{MosekModel}, ::MathOptFormat.CBF.InnerModel{Float64}, ::Bool) at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Utilities/copy.jl:340
 [7] #automatic_copy_to#97 at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Utilities/copy.jl:15 [inlined]
 [8] automatic_copy_to at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Utilities/copy.jl:14 [inlined]
 [9] #copy_to#3 at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Bridges/bridge_optimizer.jl:254 [inlined]
 [10] copy_to(::MathOptInterface.Bridges.LazyBridgeOptimizer{MosekModel}, ::MathOptFormat.CBF.InnerModel{Float64}) at /home/georgesmss/.julia/packages/MathOptInterface/A2UPd/src/Bridges/bridge_optimizer.jl:254
 [11] top-level scope at /home/georgesmss/Desktop/ProxSDP/issue.jl:17
in expression starting at /home/georgesmss/Desktop/ProxSDP/issue.jl:17

My setup is:
pkg> st
Status ~/.julia/environments/v1.2/Project.toml
[c52e3926] Atom v0.11.3
[c91e804a] Gadfly v1.1.0
[2e9cd046] Gurobi v0.7.2
[7073ff75] IJulia v1.20.0
[4076af6c] JuMP v0.20.0
[e5e0dc1b] Juno v0.7.2
[f4570300] MathOptFormat v0.2.2
[b8f27783] MathOptInterface v0.9.7
[1ec41992] MosekTools v0.9.1
[65e78d25] ProxSDP v1.2.0
[c946c3f1] SCS v0.6.2

[georgesms]

We've put this instance here:

https://gist.github.com/georgesms/0fc4c435c8a3ca9bbb1d57d0b154bc7d

The same error arises for several others.

[odow]

This is because of a combination of bridges interacting poorly with each other:
https://github.com/JuliaOpt/MathOptInterface.jl/blob/1d4f0d3fd0a545eb2c926731b7c428963092974d/src/Bridges/bridge_optimizer.jl#L1228-L1229

@blegat: what's the intended work-around? Does it need a cache? The error message should be improved.

[blegat]

Can you give the output of display(MOI.Bridges.Variable.bridges(user_model) after you get the error so that we see which variable bridge is used?

[georgesms]

Sure @blegat !

println("check 2")
display(MOI.Bridges.Variable.bridges(user_model))
try
      MOI.copy_to(user_model, mathoptformat_model)
catch e
      display(MOI.Bridges.Variable.bridges(user_model))
      println(e)
end

in the same code returns:

MathOptInterface.Bridges.Variable.Map with 0 entries
MathOptInterface.Bridges.Variable.Map with 2 entries:
  VariableIndex(-1) => ZerosBridge{Float64}(6)
  VariableIndex(-7) => ZerosBridge{Float64}(2)
ErrorException("Using bridged variable in `SingleVariable` function.")

does this answer?

[blegat]

You can use

MOI.Bridges.remove_bridge(user_model, MOI.Bridges.Variable.ZerosBridge{Float64})

as a workaround.

[georgesms]

thanks! it seems to be working.

[blegat]

Note that it should also work without the workaround on MOI master and on MOI v0.9.8 (once it is released).