Msprime: Assertion failure in DTWF with high recombination

[jeromekelleher]

When we run this simulation:

seed = 1
ts = msprime.simulate(
    100, Ne=10**4, recombination_rate=1e-4, length=10**8,
    model="dtwf", random_seed=seed)

we get

python3: lib/msprime.c:1581: msp_dtwf_generate_breakpoint: Assertion `k > start' failed.
Aborted (core dumped)

Would you mind looking into this please @daniel-goldstein?

Moved from #936.

[daniel-goldstein]

It never ends with DTWF doesn't it 🙂 . On it!