In our Windows tests in Evergreen it looks like we don't build the extension libraries in the ext/ directory and therefore don't execute the python tests that would use them.

I downloaded the artifacts from a recent Windows failure and couldn't find the libraries for compressors/nop or encrypt/rotn in the build tree.  The test output include lines such as the following showing that test_cursor08 couldn't find the compressors/nop and is therefore being skipped. 

[2021/07/07 14:30:43.997] test_cursor08.test_cursor08.test_log_cursor -s 0 (regular.nop) ... skipped 'extension "compressors/nop" not built'

Assuming we want these test to run on Windows, we might also want to change the tests to fail rather than being skipped if they can't find an extension library that is included in the WT source tree. This would ensure that we notice in the future if the libraries aren't getting built or can't be found.