Phobos unittest failure on single-core machines

[Ed McCardell]

When trying to run the phobos unittests on my 32- and 64-bit linux 
single-processor machines, I get this output:

  Testing generated/linux/debug/64/unittest/std/parallelism
  totalCPUs = 1
  core.exception.AssertError@std.parallelism(4082): unittest failure
Has anyone else seen this, or is possible that I have an error in my dmd 
setup? (I'm using dmd/druntime/phobos from git HEAD, building in what I 
thought was the normal manner).

--Ed McCardell