PaulSchuler

Hello, I had the same problem and solved it by using Ceres version 2.0.0 ([399cda7](https://github.com/ceres-solver/ceres-solver/commit/399cda773035d99eaf1f4a129a666b3c4df9d1b1).) At some point I read in another issue thread that Ceres 2.1.0 wants to use...

I got the same error except that I'm using Python 3.8 and the last line prints "-j8" instead of "-j64". I would be very happy if someone has a solution...