Improve IIS log

ext/ModelAnalyzerJuMPExt/ModelAnalyzerJuMPExt.jl

@@ -40,6 +40,13 @@ function ModelAnalyzer._name(ref::MOI.ConstraintIndex, model::JuMP.GenericModel)
     return "$jump_ref"
 end
 
+function ModelAnalyzer._show(ref::MOI.ConstraintIndex, model::JuMP.GenericModel)
+    jump_ref = JuMP.constraint_ref_with_index(model, ref)
+    io = IOBuffer()
+    show(io, jump_ref)
+    return String(take!(io))
+end
+
 """
     variable(issue::ModelAnalyzer.AbstractIssue, model::JuMP.GenericModel)
 

src/Infeasibility/summarize.jl

@@ -248,11 +248,13 @@ function ModelAnalyzer._verbose_summarize(
     issue::IrreducibleInfeasibleSubset,
     model,
 )
-    return print(
-        io,
-        "Irreducible Infeasible Subset: ",
-        join(map(x -> ModelAnalyzer._name(x, model), issue.constraint), ", "),
-    )
+    print(io, "Irreducible Infeasible Subset: ")
+    for constraint in issue.constraint
+        println(io)
+        print(io, "   ")
+        print(io, ModelAnalyzer._show(constraint, model))
+    end
+    return
 end
 
 function ModelAnalyzer.list_of_issues(data::Data, ::Type{InfeasibleBounds})

src/ModelAnalyzer.jl

@@ -219,6 +219,10 @@ function _name(ref, ::Nothing)
     return "$ref"
 end
 
+function _show(ref::MOI.ConstraintIndex, model)
+    return _name(ref, model)
+end
+
 include("Numerical/Numerical.jl")
 include("Feasibility/Feasibility.jl")
 include("Infeasibility/Infeasibility.jl")

test/test_Infeasibility.jl

@@ -572,6 +572,8 @@ function test_iis_spare()
     iis = ModelAnalyzer.constraints(ret[], model)
     @test length(iis) == 2
     @test Set(iis) == Set([c2, c1])
+    io = IOBuffer()
+    ModelAnalyzer.summarize(io, ret[1], verbose = true, model = model)
     return
 end