New comment by pullmoll on void-packages repository

https://github.com/void-linux/void-packages/pull/25724#issuecomment-712792212

Comment:
It works with the `--without-system-expat` configure option. Still, using system expat would make sense.
I don't think it's a problem to turn `expat` into `bootstrap=yes`. It's tiny compared to cmake.
Need to strip down chroot-cmake to what we really need.