restore usage of t in the error messages

Author: Datseris

docs/src/index.md

@@ -111,10 +111,10 @@ telling us exactly which variable is missing, and because of which processes it
 model = processes_to_mtkmodel(processes[[1, 3]])
 ```
 ```
-ERROR: ArgumentError: Variable x was introduced in process of variable z(t).
-However, a process for x was not provided,
-there is no default process for x, and x doesn't have a default value.
-Please provide a process for variable x.
+ERROR: ArgumentError: Variable x(t) was introduced in process of variable z(t).
+However, a process for x(t) was not provided,
+there is no default process for x(t), and (t)x doesn't have a default value.
+Please provide a process for variable x(t).
 ```
 
 If instead we "forgot" the ``y`` process, **PBM** will not error, but warn, and make ``y`` equal to a named parameter, since ``y`` has a default value:
@@ -129,8 +129,8 @@ parameters(model)
 
 and the warning thrown was:
 ```julia
-┌ Warning: Variable y was introduced in process of variable x(t).
-│ However, a process for y was not provided,
+┌ Warning: Variable y(t) was introduced in process of variable x(t).
+│ However, a process for y(t) was not provided,
 │ and there is no default process for it either.
 │ Since it has a default value, we make it a parameter by adding a process:
 │ `ParameterProcess(y)`.

src/make.jl

@@ -61,24 +61,23 @@ function processes_to_mtkmodel(_processes, _default = [];
             append_incomplete_variables!(incomplete, introduced, lhs_vars, def_proc)
         else
             def_val = default_value(added_var) # utilize default value (if possible)
-            varstr = ModelingToolkit.getname(added_var)
             if !isnothing(def_val)
                 @warn("""
-                Variable $(varstr) was introduced in process of variable $(introduced[added_var]).
-                However, a process for $(varstr) was not provided,
+                Variable $(added_var) was introduced in process of variable $(introduced[added_var]).
+                However, a process for $(added_var) was not provided,
                 and there is no default process for it either.
                 Since it has a default value, we make it a parameter by adding a process:
-                `ParameterProcess($(varstr))`.
+                `ParameterProcess($(ModelingToolkit.getname(added_var)))`.
                 """)
                 parproc = ParameterProcess(added_var)
                 push!(eqs, lhs(parproc) ~ rhs(parproc))
                 push!(lhs_vars, added_var)
             else
                 throw(ArgumentError("""
-                Variable $(varstr) was introduced in process of variable $(introduced[added_var]).
-                However, a process for $(varstr) was not provided,
-                there is no default process for $(varstr), and $(varstr) doesn't have a default value.
-                Please provide a process for variable $(varstr).
+                Variable $(added_var) was introduced in process of variable $(introduced[added_var]).
+                However, a process for $(added_var) was not provided,
+                there is no default process for $(added_var), and $(added_var) doesn't have a default value.
+                Please provide a process for variable $(added_var).
                 """))
             end
         end