Most (not all) imports are suddenly failing when run in the wingware/pro ide (v6). Imports of both library modules (e.g., math) and of my own modules from within the current directory fail in the same way:

In _bootstrap.py:

def _get_module_lock(name): """Get or create the module lock for a given module name.

Acquire/release internally the global import lock to protect
_module_locks."""

_imp.acquire_lock()
try:
    try:
        lock = _module_locks[name]()   <======== raises KeyError.
    except KeyError:
        lock = None

All of the affected programs run just find outside the IDE, no import problems.

This seems to have started after I installed pylint and mypy but uninstalling these didn't clear the problem. sys.pythonpath appears correct.

What on earth is going on?