Hello Yotam, Could you please report this as a bug on GHC Trac? https://ghc.haskell.org/trac/ghc/wiki/ReportABug I couldn’t quickly reproduce your issue, however, I run into another seemingly unrelated problem. P.S.: Note that build instructions in my blog post got slightly out of date after the Hadrian move – I’ve fixed this. Cheers, Andrey -------- Forwarded Message -------- Subject: Hadrian build failed Date: Thu, 1 Nov 2018 20:33:14 +0200 From: Yotam Ohad <yotam2206@gmail.com><mailto:yotam2206@gmail.com> To: ghc-devs@haskell.org<mailto:ghc-devs@haskell.org> Hi, I'm trying to build with hadrian (https://blogs.ncl.ac.uk/andreymokhov/building-ghc-on-windows/) I get an error when running: stack exec hadrian -- --directory ".." -j --flavour=quickest --configure md5sum: 'standard input': no properly formatted MD5 checksum lines found ERROR: mingw-w64-x86_64-crt-git-5.0.0.4795.e3d96cb1-1-any.pkg.tar.xz appears to be corrupted, please delete it and try again. ) Deleting and trying again results in the same error. Any idea on how to solve this? Yotam