hadrian: `Building and installing GHC` instructions in hadrian/README does not work

Summary

Location of documentation issue: https://gitlab.haskell.org/ghc/ghc/blob/master/hadrian/README.md

Hi, hadrian readme has a section about Building and installing GHC where it is suggested to run the command:

$ build install --prefix=/some/absolute/path

In windows i tried to run (in ghc project root):

$ ./hadrian/build.bat install --prefix=/d/bin/ghc

and the output is:

Up to date
shake: unrecognized option `--prefix=D:/bin/ghc'

Proposed improvements or changes

The more similar command i've found is binary-dist-dir but not sure if it would be equivalent and i've not found a way to set the dist-dir.

Environment

• GHC version used (if appropriate): 8.10.1