From 4ff2469f57bf77e89091791160b45dbf080a91bd Mon Sep 17 00:00:00 2001
From: Robert Vollmert <rob@vllmrt.net>
Date: Tue, 7 Jun 2022 10:23:39 +0200
Subject: [PATCH] nix: don't write to /nix/store from hsie build (fixes #2304)

This is a kind of hacky fix to the kind of hacky hsie derivation.
---
 nix/hsie/default.nix | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/nix/hsie/default.nix b/nix/hsie/default.nix
index cb627dcae..f0809c99a 100644
--- a/nix/hsie/default.nix
+++ b/nix/hsie/default.nix
@@ -16,7 +16,12 @@ let
   ghc = ghcWithPackages modules;
   hsie =
     runCommand "haskellimports" { inherit name src; }
-      "${ghc}/bin/ghc -O -Werror -Wall -package ghc $src -o $out";
+      ''
+        cd $TMP
+        cp $src $TMP/Main.hs
+        ${ghc}/bin/ghc -O -Werror -Wall -package ghc Main.hs -o Main
+        cp Main $out
+      '';
   bin =
     runCommand name { inherit hsie name; }
       ''