Recently[1] the hadrian hie-bios script was reworked to work on Windows too, and in the process the file was renamed from hie-bios to hie-bios.bat For me this broke HLS in emacs, because the new file does not have the executable flag set on my Linux checkout. Doing chmod +x hadrian/hie-bios.bat restores full functionality Alan [1] https://gitlab.haskell.org/ghc/ghc/-/commit/9df24b7e5fa8e76c01270ce1e708ab4c...