M_PI: undeclared identifier, after 0.29.18

[sciunto]

In scikit image, it appears that after the release of cython 0.29.18, a failure appeared

skimage\restoration\_unwrap_1d.c(2215): error C2065: 'M_PI': undeclared identifier

Our incriminated file: https://github.com/scikit-image/scikit-image/blob/master/skimage/restoration/_unwrap_1d.pyx
Our issue: scikit-image/scikit-image#4727
Our CI failure: https://ci.appveyor.com/project/scikit-image/scikit-image/builds/32990701/job/6oxfs51ij6fk6jqi#L840

Do you have any idea on how to fix this? Is it a bug from your or our side?

(Cc @emmanuelle)

[da-woods]

I'd guess 399a72d didn't get merged into 0.29.18?

[scoder]

I'd guess 399a72d didn't get merged into 0.29.18?

Oh, well. Yeah, sorry for that. I'll release a 0.29.19 with that fix then (4ca10b5).

[emmanuelle]

Thank you so much for the help @scoder and @da-woods :-) ❤️