Nondeterministic test failure

[btalamini]

During a PR, I got an unexpected failure in a test in the file dynamic_solid_adjoint.cpp. I say "unexpected", becaues the code introduced in my PR isn't used in that test. The failure looks like this:

48: /usr/WS1/bramwell/gl/builds/xYGwyxK_/000/gitlab/smith/serac/src/serac/physics/tests/dynamic_solid_adjoint.cpp:295: Failure
48: The difference between directional_deriv and (qoi_plus - qoi_base) / eps is nan, which exceeds eps, where
48: directional_deriv evaluates to -nan,
48: (qoi_plus - qoi_base) / eps evaluates to -0.023019492978448852, and
48: eps evaluates to 1.9999999999999999e-07.
48: 
48: [  FAILED  ] SolidMechanicsSensitivityFixture.ShapeSensitivities (7280 ms)

I'm suspicious that we have some kind of non-deterministic problem here, like a race condition. The entire log is included below.

output.log.make.test.txt

[btalamini]

There was an indexing error (going past the end of the array). The error was intermittent, because the retrieved value was being multiplied by 0 - it wouldn't affect the results, so long as the memory read beyond the end of the array could be interpreted as a double. Otherwise, a NAN was issued and would cause the test to fail. This is closed by #1183