@bmispelon I think it’s a change from Python 3. Previously, cyclical imports would fail unless you only imported already defined symbols by name. It had its own WTFs as you could later redefine a symbol that was already exported. In Python 3 it instead keeps building each module in place until complete or deadlocked, so you get A = 1, block, A gets imported into b, A is increased, a gets unblocked, a imports A back. I’m sure there is a valid use case