I'm getting the same error! Did you manage to figure it out?
Posted in Setup MacOS 11.0 Big Sur Discussion
I'm having issues with the sudo installer. Tried to install XCode like the comments above but still get the error below.
installer: Error - the package path specified was invalid: '/Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg'.
Any way to fix this?