To reproduce:
- Add a repo to Trac
- Use the multireposearchplugin's sqlindexer to index the repo's files
- Remove the repo from the filesystem, but leave it configured in Trac
- Search for a term that exists in the repo's file contents
The system will throw a different error depending on the version control backend used. For Git, it will look like /path/to/repository.git/ does not appear to be a Git repository.
Instead of throwing a system error, this exception should be caught and logged, and the offending search result should be ignored.