Revert "Extend Haskell generic builder to use new --ipid flag."

This reverts commit ec8b81615462625338d76f002d92accd6eb4cf6a. The change told
the Cabal build system to use the hash-part of $out as the internal identifier
for the library it's building (rather than generating such an ID itself). While
a good idea in theory, this choice had an unfortunate side-effect: When Cabal
links libraries X, Y, and Z into an executable, then the generated binary
contains their respective IDs. Now, Nix finds those strings and treats them as
an indication that there is a *run-time dependency* on the corresponding store
paths. This means that the generated executable will always depend on the store
paths of all the Haskell libraries that went into it, even when linked
statically.

1 files changed, 0 insertions, 5 deletions

diff --git a/pkgs/development/haskell-modules/generic-builder.nix b/pkgs/development/haskell-modules/generic-builder.nix
index e4fcd09c0e03..2b597532b44d 100644
--- a/pkgs/development/haskell-modules/generic-builder.nix
+++ b/pkgs/development/haskell-modules/generic-builder.nix
@@ -180,11 +180,6 @@ stdenv.mkDerivation ({
     setupCompileFlags="${concatStringsSep " " setupCompileFlags}"
     configureFlags="${concatStringsSep " " defaultConfigureFlags} $configureFlags"
 
-    ${optionalString (stdenv.lib.versionOlder "8" ghc.version) ''
-      ipid=$(echo $(basename "$out") | cut -d- -f1)
-      configureFlags+=" --ipid=$ipid"
-    ''}
-
     local inputClosure=""
     for i in $propagatedNativeBuildInputs $nativeBuildInputs; do
       findInputs $i inputClosure propagated-native-build-inputs