Change error msg for GetAttributeNotAllowed when is_set_by_optimize

src/attributes.jl

@@ -129,6 +129,37 @@ operation_name(err::GetAttributeNotAllowed) = "Getting attribute $(err.attr)"
 
 message(err::GetAttributeNotAllowed) = err.message
 
+function fix_message(err::GetAttributeNotAllowed)
+    if is_set_by_optimize(err.attr)
+        return """
+        ## Fixing this error
+
+        This error occurs when we cannot query the attribute from the solver.
+        No other information is available. Check the solver log for details.
+        """
+    end
+    return """
+    ## Fixing this error
+
+    An `MOI.NotAllowedError` error occurs when you have tried to do something that
+    is not implemented by the solver.
+
+    The most common way to fix this error is to wrap the optimizer in a
+    `MOI.Utilities.CachingOptimizer`.
+
+    For example, if you are using `JuMP.Model` or `JuMP.set_optimizer`, do:
+    ```julia
+    model = JuMP.Model(optimizer; with_cache_type = Float64)
+    model = JuMP.GenericModel{T}(optimizer; with_cache_type = T)
+    JuMP.set_optimizer(model, optimizer; with_cache_type = Float64)
+    ```
+    Similarly, if you are using `MOI.instantiate`, do:
+    ```julia
+    model = MOI.instantiate(optimizer; with_cache_type = Float64)
+    ```
+    """
+end
+
 """
     AbstractSubmittable
 

src/error.jl

@@ -61,32 +61,33 @@ function Base.showerror(io::IO, err::NotAllowedError)
         println(io, " because:\n\n", m)
     end
     println(io)
-    print(
-        io,
-        """
-        ## Fixing this error
-
-        An `MOI.NotAllowedError` error occurs when you have tried to do something that
-        is not implemented by the solver.
-
-        The most common way to fix this error is to wrap the optimizer in a
-        `MOI.Utilities.CachingOptimizer`.
-
-        For example, if you are using `JuMP.Model` or `JuMP.set_optimizer`, do:
-        ```julia
-        model = JuMP.Model(optimizer; with_cache_type = Float64)
-        model = JuMP.GenericModel{T}(optimizer; with_cache_type = T)
-        JuMP.set_optimizer(model, optimizer; with_cache_type = Float64)
-        ```
-        Similarly, if you are using `MOI.instantiate`, do:
-        ```julia
-        model = MOI.instantiate(optimizer; with_cache_type = Float64)
-        ```
-        """,
-    )
+    print(io, fix_message(err))
     return
 end
 
+function fix_message(::NotAllowedError)
+    return """
+    ## Fixing this error
+
+    An `MOI.NotAllowedError` error occurs when you have tried to do something that
+    is not implemented by the solver.
+
+    The most common way to fix this error is to wrap the optimizer in a
+    `MOI.Utilities.CachingOptimizer`.
+
+    For example, if you are using `JuMP.Model` or `JuMP.set_optimizer`, do:
+    ```julia
+    model = JuMP.Model(optimizer; with_cache_type = Float64)
+    model = JuMP.GenericModel{T}(optimizer; with_cache_type = T)
+    JuMP.set_optimizer(model, optimizer; with_cache_type = Float64)
+    ```
+    Similarly, if you are using `MOI.instantiate`, do:
+    ```julia
+    model = MOI.instantiate(optimizer; with_cache_type = Float64)
+    ```
+    """
+end
+
 """
     message(err::Union{UnsupportedError, NotAllowedError})
 

test/General/errors.jl

@@ -361,6 +361,7 @@ function test_get_fallback_error()
         contents,
     )
     @test occursin("## Fixing this error", contents)
+    @test occursin("No other information is available", contents)
     return
 end
 
@@ -409,6 +410,18 @@ function test_logs_precompile()
     return
 end
 
+function test_GetAttributeNotAllowed_showerror()
+    c_set = sprint(showerror, MOI.GetAttributeNotAllowed(MOI.ConstraintSet()))
+    @test occursin("## Fixing this error", c_set)
+    @test occursin("MOI.Utilities.CachingOptimizer", c_set)
+    @test !occursin("Check the solver log for details.", c_set)
+    c_dual = sprint(showerror, MOI.GetAttributeNotAllowed(MOI.ConstraintDual()))
+    @test occursin("## Fixing this error", c_dual)
+    @test !occursin("MOI.Utilities.CachingOptimizer", c_dual)
+    @test occursin("Check the solver log for details.", c_dual)
+    return
+end
+
 end  # module
 
 TestErrors.runtests()