Comment 1 for bug 993247

It turns out that AssemblyReader opens a dll and closes it in AssemblyReader.Dispose. However, AssemblyResolver that creates AssemblyReader never disposes it, so the files stays open until eventually GC calls Dispose. On Linux this causes us to eventually run out of file handles.

Attached is a suggested fix. I did not include a unit test because I don't know how I could test this specific scenario.