Yes, we discussed this with @jcfr today, and if I understood correctly, something has changed on the factory machine about 27 days ago, which broke packaging of the pywt extension. JC was going to change something on the factory to fix this.
In the interim, I was able to make the module work again by manually installing the missing packages from the Slicer python console:
>>> slicer.util.pip_install('pywavelets')
>>> slicer.util.pip_install('python-dateutil')