Hadrian build on branch 9.0 fails with `No generator for _build/stage0/.../Platform/ARM64.hs.`

Summary

Unable to compile branch ghc-9.0. Compilation stops after the error No generator for _build/stage0/compiler/build/GHC/Platform/ARM64.hs.

Steps to reproduce

Check out branch ghc-9.0
Pull recursive with submodules from upstream ghc-9.0 and update submodules
hadrian/build clean
hadrian/build --flavour=devel2 -j2

Here are the last lines of the log before the failure:

| Run DeriveConstants: none => _build/stage0/lib/DerivedConstants.h (and 1 more)
| Run Ghc CompileHs Stage0: libraries/parsec/src/Text/ParserCombinators/Parsec/Pos.hs => _build/stage0/libraries/parsec/build/Text/ParserCombinators/Parsec/Pos.o
Error when running Shake build system:
  at action, called at src/Rules.hs:40:19 in main:Rules
  at need, called at src/Rules.hs:62:5 in main:Rules
* Depends on: _build/stage0/lib/package.conf.d/ghc-9.0.0.20201127.conf
  at need, called at src/Rules/Register.hs:119:5 in main:Rules.Register
* Depends on: _build/stage0/compiler/build/libHSghc-9.0.0.20201127.a
  at need, called at src/Rules/Library.hs:152:5 in main:Rules.Library
* Depends on: _build/stage0/compiler/build/GHC/Tc/Gen/Export.o
  at &%>, called at src/Rules/Compile.hs:77:9 in main:Rules.Compile
* Depends on: _build/stage0/compiler/build/GHC/Tc/Gen/Export.o _build/stage0/compiler/build/GHC/Tc/Gen/Export.hi
  at apply1, called at src/Development/Shake/Internal/Rules/Oracle.hs:159:32 in shake-0.18.5-ff2d55bc7a583713dacf2cc182c92c161d6347d3b0f20f7dd27741dbc345a51c:Development.Shake.Internal.Rules.Oracle
* Depends on: OracleQ (KeyValues ("_build/stage0/compiler/.dependencies","_build/stage0/compiler/build/GHC/Tc/Gen/Export.o"))
  at need, called at src/Hadrian/Oracles/TextFile.hs:96:9 in main:Hadrian.Oracles.TextFile
* Depends on: _build/stage0/compiler/.dependencies
  at readFile', called at src/Rules/Dependencies.hs:34:19 in main:Rules.Dependencies
  at need, called at src/Development/Shake/Internal/Derived.hs:118:15 in shake-0.18.5-ff2d55bc7a583713dacf2cc182c92c161d6347d3b0f20f7dd27741dbc345a51c:Development.Shake.Internal.Derived
* Depends on: _build/stage0/compiler/.dependencies.mk
  at need, called at src/Rules/Dependencies.hs:26:9 in main:Rules.Dependencies
* Depends on: _build/stage0/compiler/build/GHC/Platform/ARM64.hs
  at error, called at src/Rules/Generate.hs:102:34 in main:Rules.Generate
* Raised the exception:
No generator for _build/stage0/compiler/build/GHC/Platform/ARM64.hs.

Expected behavior

Should build stage0 and stage 1 of the GHC compiler

Environment

GHC version used: 8.10.2

Optional:

Operating System: Debian 10
System Architecture: x68_64

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