Interesting that static version is 8.4, but pathlevel is 8.5.9. It means that Tkinter is built with older version of headers and does not support bignum type, but dynamically linked to newer library which can create bignum objects.

There is a problem with tests. They should be skipped if Tkinter is built with old Tcl headers (it is not easy to do reliable). But there is also a problem with configuration which founds too old headers.