python3-all-dev 3.5.1-4 (armhf binary) in ubuntu zesty

 The package currently depends on python3.5-dev, in the
 future, dependencies on jython (Python for a JVM) and ironpython (Python
 for Mono) may be added.
 .
 This package is a dependency package used as a build dependency for other
 packages to avoid hardcoded dependencies on specific Python 3 development
 packages.