Assignment rule variable not found when variable is a Parameter

[BryanRumsey]

Model

I used the degradation/decay model with an added assignment rule setting decayrate to 10.

Solver

Simulated using the TauHybridSolver

Error

Compute Environment: Local
2023-05-02 15:34:54,573 - GillesPy2 - ERROR - Job errors: argument 'solver=' to run() failed. Reason Given: 'decayrate' is not in list
Traceback (most recent call last):
File "/opt/conda/lib/python3.8/site-packages/gillespy2/core/model.py", line 1295, in run
return solver.run(t=t, increment=increment, timeout=timeout, **solver_args)
File "/opt/conda/lib/python3.8/site-packages/gillespy2/solvers/numpy/tau_hybrid_solver.py", line 1129, in run
raise self.has_raised_exception
File "/opt/conda/lib/python3.8/site-packages/gillespy2/solvers/numpy/tau_hybrid_solver.py", line 1138, in ___run
self.__run(curr_state, curr_time, timeline, trajectory_base, initial_state, live_grapher, t,
File "/opt/conda/lib/python3.8/site-packages/gillespy2/solvers/numpy/tau_hybrid_solver.py", line 1272, in __run
sol, curr_state[0], curr_time[0], save_times, save_index = self.__simulate(integrator_options,
File "/opt/conda/lib/python3.8/site-packages/gillespy2/solvers/numpy/tau_hybrid_solver.py", line 676, in __simulate
save_index = self.__save_state_to_output(
File "/opt/conda/lib/python3.8/site-packages/gillespy2/solvers/numpy/tau_hybrid_solver.py", line 124, in __save_state_to_output
trajectory[trajectory_index][species.index(ar.variable.name) + 1] = assignment_value
ValueError: 'decayrate' is not in list

[briandrawert]

TODO:

• Update documentation: parameter can not be targets of assignment rules, rate rules, or events
• Throw exception when parameter is used as target. (check in the compile-prep function, and the "add_" function)
• Update tests
• On SBML import, anytime a parameter is a target, convert it to a species (might be already done).
• Update StochSS: interface should state that parameters can not be targets (suggest they change to a species)