Some file can't be tracked by Commits.QueryBy(path)

[wenlong-xyz]

I use to following code to track the latest change for a special file. But I found some file can't be tracked while the others can be tracked correctly.

var latestCommitLog = repository.Commits.QueryBy(file);
if (latestCommitLog.Count() > 0)
{
        var latestCommit = latestCommitLog.First().Commit;
}
else 
{
        // no history
        // some file has be pushed to repository but can't be tracked.
}