do not support linear constraints with constant offset

 - because I would need to merge it with lhs/rhs
 - but then I can not modify the constraint with set(, ConstraintSet, )
 - so I just throw AddConstraintNotAllowed

src/MOI_wrapper.jl

@@ -154,20 +154,41 @@ end
 
 function MOI.add_constraint(o::Optimizer, func::MOI.ScalarAffineFunction{Float64},
  set::S) where {S <: SS}
+ if func.constant != 0.0
+ msg = "SCIP does not support linear constraints with a constant offset."
+ throw(MOI.AddConstraintNotAllowed{MOI.ScalarAffineFunction{Float64}, S}(msg))
+ end
+
  allow_modification(o)
  scip = get_scip(o)
 
  varidx = [t.variable_index.value for t in func.terms]
  coefs = [t.coefficient for t in func.terms]
 
  lhs, rhs = bounds(set)
- lhs = lhs == nothing ? -SCIPinfinity(scip) : lhs - func.constant
- rhs = rhs == nothing ? SCIPinfinity(scip) : rhs - func.constant
+ lhs = lhs == nothing ? -SCIPinfinity(scip) : lhs
+ rhs = rhs == nothing ? SCIPinfinity(scip) : rhs
 
  i = add_linear_constraint(o.mscip, varidx, coefs, lhs, rhs)
  return register!(o, CI{MOI.ScalarAffineFunction{Float64}, S}(i))
 end
 
+function MOI.set(o::SCIP.Optimizer, ::MOI.ConstraintSet,
+ ci::CI{MOI.ScalarAffineFunction{Float64},S}, set::S) where {S <: SS}
+ allow_modification(o)
+ scip = get_scip(o)
+ cons = get_cons(o, ci)
+
+ lhs, rhs = bounds(set)
+ lhs = lhs == nothing ? -SCIPinfinity(scip) : lhs
+ rhs = rhs == nothing ? SCIPinfinity(scip) : rhs
+
+ @SC SCIPchgLhsLinear(scip, cons, lhs)
+ @SC SCIPchgRhsLinear(scip, cons, rhs)
+
+ return nothing
+end
+
 function MOI.get(o::Optimizer, ::MOI.NumberOfConstraints{F,S}) where {F,S}
  haskey(o.cons, (F, S)) ? length(o.cons[F, S]) : 0
 end