SLiM Migration Rate Error

[raywray]

I have another SLiM error:

Traceback (most recent call last):
  File "/home/resplin5072/Projects/CoalMinerExamples/simulation_scripts/python/generate_data_stdpopsim.py", line 101, in <module>
    generate_stdpopsim_data()
  File "/home/resplin5072/Projects/CoalMinerExamples/simulation_scripts/python/generate_data_stdpopsim.py", line 98, in generate_stdpopsim_data
    get_ara_tha_data()
  File "/home/resplin5072/Projects/CoalMinerExamples/simulation_scripts/python/generate_data_stdpopsim.py", line 92, in get_ara_tha_data
    generate_data(species, model, contig, samples)
  File "/home/resplin5072/Projects/CoalMinerExamples/simulation_scripts/python/generate_data_stdpopsim.py", line 38, in generate_data
    ts = engine.simulate(model, contig, samples, slim_scaling_factor=scaling_factor, slim_burn_in=10.0)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/resplin5072/miniconda3/envs/coalminer_examples_env/lib/python3.12/site-packages/stdpopsim/slim_engine.py", line 1586, in simulate
    self._run_slim(
  File "/home/resplin5072/miniconda3/envs/coalminer_examples_env/lib/python3.12/site-packages/stdpopsim/slim_engine.py", line 1673, in _run_slim
    raise SLiMException(
stdpopsim.slim_engine.SLiMException: slim exited with code 1.
ERROR (Population::SetMigration): migration fraction has to be within [0,1] (2.0 supplied).

Error on script line 1, character 22 (inside runtime script block):

{dbg(self.source); p1.setMigrationRates(0, 2.0);}
                      ^^^^^^^^^^^^^^^^^

This happens when I run this code:

def generate_data(species, model, contig, samples, scaling_factor=10):
    # define outputs
    stdpop_output_dir = "stdpop_output"
    vcf_dir = os.path.join(stdpop_output_dir, "vcf")
    slim_dir = os.path.join(stdpop_output_dir, "slim_scripts")
    
    vcf_file_path = os.path.join(vcf_dir, f"{species.id}.vcf")
    slim_file_path = os.path.join(slim_dir, f"{species.id}.slim")

    utilities.create_directory(stdpop_output_dir)
    utilities.create_directory(vcf_dir)
    utilities.create_directory(slim_dir)
    
    # step 5: select engine
    engine = stdpopsim.get_engine("slim")
    
    # write slim script to file
    with open(slim_file_path, "w") as f:
        with redirect_stdout(f):
            ts = engine.simulate(
                model,
                contig,
                samples,
                slim_script=True,
                verbosity=2,
                slim_scaling_factor=scaling_factor,
                slim_burn_in=10.0
            )
    # step 6: simulate
    ts = engine.simulate(model, contig, samples, slim_scaling_factor=scaling_factor, slim_burn_in=10.0)

    if ts is None:
        print("Simulation failed, no tree sequence generated.")
        return
    else:
        # write vcf
        with open(vcf_file_path, "w") as vcf_file:
            ts.write_vcf(vcf_file, contig_id="0")
def get_ara_tha_data():
    print("**********************ARA THA*************************")
    species = stdpopsim.get_species("AraTha")
    model = stdpopsim.IsolationWithMigration(
        NA=5000, N1=4000, N2=1000, T=1000, M12=0.1, M21=0.2
    )
    contig = species.get_contig("chr4", genetic_map="SalomeAveraged_TAIR10")
    samples = {"pop1": 5, "pop2": 5}

    generate_data(species, model, contig, samples)

You can see that I've set the migration rates to 0.1 and 0.2, not 2.0 like the error suggests. I'm wondering if the translation to SLiM has some kind of miscommunication. If helpful, I can include the generated SLiM script.