See the discussion on #2174. An uncaught C++ error on main causes an error like:
```
TypeError: Cannot create property 'pyodide_fatal_error' on number '28811048'
```
With this the same error looks like:
```
Pyodide has suffered a fatal error. Please report this to the Pyodide maintainers.
The cause of the fatal error was:
CppException: Unable to cast Python instance to C++ type (compile in debug mode for details)
```
Support for C++ exceptions in packages. See the discussion on #2174. An uncaught C++ error on main causes an error like:
```
TypeError: Cannot create property 'pyodide_fatal_error' on number '28811048'
```
With this the same error looks like:
```
Pyodide has suffered a fatal error. Please report this to the Pyodide maintainers.
The cause of the fatal error was:
CppException: Unable to cast Python instance to C++ type (compile in debug mode for details)
```
package:
  name: nose
  version: 1.3.7

source:
  url: https://files.pythonhosted.org/packages/15/d8/dd071918c040f50fa1cf80da16423af51ff8ce4a0f2399b7bf8de45ac3d9/nose-1.3.7-py3-none-any.whl
  sha256: 9ff7c6cc443f8c51994b34a667bbcf45afd6d945be7477b52e97516fd17c53ac

requirements:
  run:
    - setuptools

test:
  imports:
    - nose

package:
  name: nose
  version: 1.3.7

source:
  url: https://files.pythonhosted.org/packages/15/d8/dd071918c040f50fa1cf80da16423af51ff8ce4a0f2399b7bf8de45ac3d9/nose-1.3.7-py3-none-any.whl
  sha256: 9ff7c6cc443f8c51994b34a667bbcf45afd6d945be7477b52e97516fd17c53ac

requirements:
  run:
    - setuptools

test:
  imports:
    - nose
