runtime: Unable to cross-build for Android

After downloading a fresh Ubuntu VM, checking out all dependencies, and building CoreCLR and CoreFX, I tried to run cross/build-android-rootfs.sh.

First it gave me an error:

wget unrecognized option '--show-progress'

After removing this option from the command line, the script proceeded until the “Unpacking termux packages” stage, at which all of the operations errored out with:

dpkg-deb: error: archive [name] has premature member ‘control.tar.xz’ before ‘control.tar.gz’, giving up

No idea what to do about this error.