run-tests.py: tell coverage.py to ignore errors
Otherwise there'll be some IOErrors when it tries to open python
files created during the execution of e.g. test-hook.
#!/bin/sh
hg init dir
cd dir
echo bleh > bar
hg add bar
hg ci -m 'add bar'
hg cp bar foo
echo >> bar
hg ci -m 'cp bar foo; change bar'
hg debugrename foo
hg debugindex .hg/store/data/bar.i