@DuyTrandeLion @Vitalii_S @pynqzen @fpgadeveloper
Guys, this is because of this line:
https://github.com/Xilinx/PYNQ/blob/master/sdbuild/packages/python_packages_bionic/qemu.sh#L51
The latest pip changed the way it resolves dependency. This is a new thing just changed in Oct 2020. The quick fix will be to fix the pip version to an older one. I will need to look into this and propose a fix.
At this time you can use the prebuilt image for build just as a temporary workaround.