fitted line map caused crash in cubeviz

[SaOgaz]

Text from issue posted in cubeviz (spacetelescope/cubeviz#532):
Does this go in the specviz repo?

During a test session with @bethanjames, testing out the fitted line maps over some MUSE data, cubeviz crashed. Here's the trace back. Apologies for the bad formatting, can't seem to get it to look nicer.

WARNING: UnitsWarning: '10**(-20)*erg/s/cm2/Angstrom' contains multiple slashes, which is discouraged by the FITS standard [astropy.units.format.generic]
WARNING:astropy:UnitsWarning: '10(-20)*erg/s/cm2/Angstrom' contains multiple slashes, which is discouraged by the FITS standard
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specutils/utils/wcs_utils.py:244: UserWarning: Support for air wavelengths is experimental and only works in the forward direction (air->vac, not vac->air).
warnings.warn("Support for air wavelengths is experimental and only "
WARNING: UnitsWarning: '10(-20)*erg/s/cm2/Angstrom' contains multiple slashes, which is discouraged by the FITS standard [astropy.units.format.generic]
WARNING:astropy:UnitsWarning: '10(-20)*erg/s/cm2/Angstrom' contains multiple slashes, which is discouraged by the FITS standard
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specutils/utils/wcs_utils.py:244: UserWarning: Support for air wavelengths is experimental and only works in the forward direction (air->vac, not vac->air).
warnings.warn("Support for air wavelengths is experimental and only "
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/numpy/lib/function_base.py:3250: RuntimeWarning: Invalid value encountered in median
r = func(a, kwargs)
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/numpy/lib/function_base.py:3250: RuntimeWarning: Invalid value encountered in median
r = func(a, kwargs)
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/numpy/lib/function_base.py:3250: RuntimeWarning: Invalid value encountered in median
r = func(a, kwargs)
WARNING: UnitsWarning: '10(-20)*erg/s/cm2/Angstrom' contains multiple slashes, which is discouraged by the FITS standard [astropy.units.format.generic]
WARNING:astropy:UnitsWarning: '10(-20)*erg/s/cm2/Angstrom' contains multiple slashes, which is discouraged by the FITS standard
Traceback (most recent call last):
File "/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specviz/widgets/workspace.py", line 227, in _on_item_changed
proxy_index = self.list_view.model().mapFromSource(plot_item.data_item.index())
RuntimeError: wrapped C/C++ object of type DataItem has been deleted
Traceback (most recent call last):
File "/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specviz/widgets/workspace.py", line 227, in _on_item_changed
proxy_index = self.list_view.model().mapFromSource(plot_item.data_item.index())
RuntimeError: wrapped C/C++ object of type DataItem has been deleted
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specutils/utils/wcs_utils.py:244: UserWarning: Support for air wavelengths is experimental and only works in the forward direction (air->vac, not vac->air).
warnings.warn("Support for air wavelengths is experimental and only "
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/numpy/lib/function_base.py:3250: RuntimeWarning: Invalid value encountered in median
r = func(a, **kwargs)
/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specutils/utils/wcs_utils.py:244: UserWarning: Support for air wavelengths is experimental and only works in the forward direction (air->vac, not vac->air).
warnings.warn("Support for air wavelengths is experimental and only "
Traceback (most recent call last):
File "/Users/bjames/miniconda3/envs/cubeviz-testing/lib/python3.6/site-packages/specviz/widgets/workspace.py", line 227, in _on_item_changed
proxy_index = self.list_view.model().mapFromSource(plot_item.data_item.index())
RuntimeError: wrapped C/C++ object of type DataItem has been deleted
Segmentation fault: 11