ghc 9.6.2 fails to build on macOS because of missing docs/index.html

Summary

ghc 9.6.2 fails to build on macOS because of a missing file docs/index.html. The file ./docs/index.html.in exists, but apparently is not converted to docs/index.html. The same exact build procedure works for version 9.6.1.

Steps to reproduce

hadrian binary-dist-dir -j24

Observe successful bootstrap that fails with creation of the docs:

:info:build | Run Haddock BuildPackage: libraries/Cabal/Cabal/src/Distribution/Backpack/ComponentsGraph.hs (and 114 more) => _build/doc/html/libraries/Cabal-3.10.1.0/Cabal.haddock
:info:build | Run Haddock BuildIndex: _build/doc/html/libraries/binary-0.8.9.1/binary.haddock (and 35 more) => _build/doc/html/libraries/index.html
:info:build | Copy file (untracked): docs/index.html => _build/doc/html/index.html
:info:build docs/index.html: copyFile:atomicCopyFileContents:withReplacementFile:copyFileToHandle:openFdAt: does not exist (No such file or directory)
:info:build Build failed.

Expected behavior

Bootrsap the compiler.

Environment

• GHC version used: 9.6.2

Optional:

• Operating System: macOS
• System Architecture: x86_64