Friends

My GHC builds have started falling over with

| Copy file: _build/stage1/bin/runghc => _build/bindist/ghc-10.1.20260702-x86_64-unknown-linux/bin/runghc-10.1.20260702
| Copy directory: _build/stage1/lib => _build/bindist/ghc-10.1.20260702-x86_64-unknown-linux
]0;Running for 9m50s [36386/36406], predicted 1s (99%)(/home/simonpj/code/HEAD) ]0;Running for 9m55s [36386/36406], predicted 1s (99%)(/home/simonpj/code/HEAD) | Copy directory: _build/stage1/lib/x86_64-linux-ghc-10.1.20260702/rts-1.0.3/include => _build/bindist/ghc-10.1.20260702-x86_64-unknown-linux
# ghc-pkg (for binary-dist-dir)
]0;Finished in 10m00s(/home/simonpj/code/HEAD) Non optional builder 'sphinx-build' is not specified in 'hadrian/cfg/system.config' file.
Build failed.

What should I do?  Thanks

Simon