New comment by sgn on void-packages repository

https://github.com/void-linux/void-packages/issues/45679#issuecomment-1868669407

Comment:
> If cmake in xbps-src is supposed to not support downloads at all, then the error message should be that, "This cmake-bootstrap build does not support downloads", or the like

It supports `file(DOWNLOAD)` but only `file://` protocol.