Make all tests pass.

src/macros.jl

@@ -444,7 +444,7 @@ function parse_ternary_constraint(_error::Function, args...)
     _error("Only two-sided rows of the form lb <= expr <= ub or ub >= expr >= lb are supported.")
 end
 
-function parse_constraint(_error::Function, ::Val{:comparison}, lb, lsign::Symbol, aff, rsign::Symbol, ub)
+function parse_constraint(_error::Function, zer::Val{:comparison}, lb, lsign::Symbol, aff, rsign::Symbol, ub)
     (lsign, lvectorized) = _check_vectorized(Val(lsign))
     (rsign, rvectorized) = _check_vectorized(Val(rsign))
     ((vectorized = lvectorized) == rvectorized) || _error("Signs are inconsistently vectorized")
@@ -627,8 +627,12 @@ function _constraint_macro(args, macro_name::Symbol, parsefun::Function)
     if x.head == :(:=)
         vectorized = false
         parsecode, buildcall = parse_reification_constraint(_error, x)
-    else
+    elseif x.head == :comparison
         # First dispatch on head, to deal with lb <= x <= ub specifically.
+        # Do not wrap the first argument in Val, as it is a part of the comparison
+        # (unlike the normal case, :call:, where it is an operator/function).
+        vectorized, parsecode, buildcall = parsefun(_error, Val(x.head), x.args...)
+    else
         vectorized, parsecode, buildcall = parsefun(_error, Val(x.head), Val(x.args[1]), x.args[2:end]...)
     end