Bad things are happening.   I can’t build GHC at all!

I’m trying ‘sh validate –fast’ on a clean build of a master checkout

HEAD detached at 3a96a0b6db

(this is the master checkout from which !2276 branches off)

But alas I get this

Exit code: 1

Stderr:

compiler/main/DynFlags.hs:323:0: error:

     error: "GHC_STAGE" is not defined, evaluates to 0 [-Werror=undef]

     #if GHC_STAGE >= 2

    |

323 | #if GHC_STAGE >= 2

    | ^

compiler/main/DynFlags.hs:5750:0: error:

     error: "GHC_STAGE" is not defined, evaluates to 0 [-Werror=undef]

     #if GHC_STAGE < 2

     |

5750 | #if GHC_STAGE < 2

     | ^

cc1: all warnings being treated as errors

What should I do?

Simon