Matt McCormick

@jond01 outstanding investigation! :clap: Many codes, including ITK, assume that spacing is a physical length that will always be positive, and undefined behavior, which may be wrong, can result when...

It may be that pip is not resolving package dependencies correctly. It is best to start from a clean virtual environment / conda environment.

@YannLePoul cool! Could a test please be added?

@mrocklin thanks for the report. We will dive deeper into this. :xref: #1065 , which was not sufficient.

I am wondering if the observed behavior was related to: https://github.com/InsightSoftwareConsortium/ITK/commit/cfdb5023a82fc61f3825231b257ca47f4d9d4d8a or https://github.com/InsightSoftwareConsortium/ITK/issues/2069

@jjjkkyz thanks for the report. Does the same issue occur with ITK Git `master`?

Remote modules will need to be updated to build against the latest ITK -- we do not have binary compatibility with remote modules across ITK versions.

ITK git `master` now has https://github.com/InsightSoftwareConsortium/ITK/pull/3541 -- as suggested by @hubutui this may help with this issue.

> ITK-5.2.1 @badshah400 thanks for testing. Is it possible to test Git `master`?

@hjmjohnson what was the use case where https://github.com/InsightSoftwareConsortium/ITK/commit/ee989dc89afa3487bf0ec1e730e0bdb8ebea38a2 was needed?