S-lang-related Bugs: run_cov

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Bugs

Running any Sherpa/S-Lang module function that involves matrix inversion results in a SegV.
(Mac OS X)

e.g. run_fit with LM, run_proj with LM, run_cov with any optimizer.

Workarounds:

Use the analogous Sherpa commands - fit, projection, covariance - which work correctly.
For fitting and projection, change to an optimizer that doesn't rely on matrix inversion (that is, any optimizer but LM).