From eb86e867694bceedfb47a527d71429197ffe6dda Mon Sep 17 00:00:00 2001
From: Tobias Dammers <tdammers@gmail.com>
Date: Mon, 27 Nov 2017 14:00:50 -0500
Subject: [PATCH] Don't call alex for Cabal lib during GHC build

The Cabal library now commits `Lexer.hs` directly to the source tree,
so the build step where we'd call alex ourselves to generate that file
is no longer necessary, nor will it work.

See also: https://ghc.haskell.org/trac/ghc/ticket/14459

Reviewers: bgamari, hvr

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14459

Differential Revision: https://phabricator.haskell.org/D4240
---
 ghc.mk | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/ghc.mk b/ghc.mk
index e653aae88f26..38c165d26136 100644
--- a/ghc.mk
+++ b/ghc.mk
@@ -1257,7 +1257,15 @@ $(eval $(call sdist-ghc-file,compiler,stage2,parser,Parser,y))
 $(eval $(call sdist-ghc-file,utils/hpc,dist-install,,HpcParser,y))
 $(eval $(call sdist-ghc-file,utils/genprimopcode,dist,,Lexer,x))
 $(eval $(call sdist-ghc-file,utils/genprimopcode,dist,,Parser,y))
-$(eval $(call sdist-ghc-file2,libraries/Cabal/Cabal,dist-install,Distribution/Parsec,Lexer,x))
+
+# Recent Cabal library versions have a pre-generated Lexer.hs in the source
+# repo, and have moved Lexer.x out of the way, so trying to generate it from
+# here no longer works, and is no longer necessary.
+# According to https://github.com/haskell/cabal/issues/4633 however, this is
+# only a temporary solution, so we will probably have to adjust to whatever
+# the proper solution is going to be once there is one.
+#
+# $(eval $(call sdist-ghc-file2,libraries/Cabal/Cabal,dist-install,Distribution/Parsec,Lexer,x))
 
 .PHONY: sdist-ghc-prep
 sdist-ghc-prep : sdist-ghc-prep-tree
-- 
GitLab