install stage0 libraries?

[Norman Ramsey]

If I understand correctly, the way Hadrian works is that all of the
.conf files, binaries, and so on in _build/stage0 are built with the
bootstrap compiler.  I need to write client code that uses the ghc
library built from GHC HEAD (so ghc-9.3), but I'd prefer to use the
bootstrap compiler.  (The HLS works with the bootstrap compiler.)

Is there a way to get Hadrian to install the stage0 libraries in a way
that cabal-install can find it using standard options?  I tried to do
it myself using `ghc-pkg register`, and all I accomplished was to make
an unrecoverable mess of my system.

(The problem I'm trying to solve is to get my client code to compile
against the latest library, while also enabling the HLS to find all
the things.)


Norman