From 9f7560d25b01dbc037acadc3a4e4f3778169839d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix=20Baylac=20Jacqu=C3=A9?=
 <felix@alternativebit.fr>
Date: Fri, 20 Dec 2019 10:29:26 +0100
Subject: [PATCH] shell repro

---
 README.md                  | 40 +++-----------------------------------
 cabal.project              |  3 ++-
 dummy-app/app/dummy-app.hs |  2 +-
 shell.nix                  | 15 ++++++++++++++
 4 files changed, 21 insertions(+), 39 deletions(-)
 create mode 100644 shell.nix

diff --git a/README.md b/README.md
index 09aa56c..adbe03f 100644
--- a/README.md
+++ b/README.md
@@ -1,39 +1,5 @@
 # `haskell-nix.cabalProject` bug minimal repro
 
-1. Clone this repo.
-2. Run `nix build -f . dummy-app.components.exes.dummy-app`.
-
-Expected output:
-
-```
-trace: Using latest index state!
-trace: Using index-state: 2019-12-14T00:00:00Z
-builder for '/nix/store/g5023y5h06iy1bj076zzaaza0v8c80w3-plan-to-nix-pkgs.drv' failed with exit code 128; last 2 log lines:
-  Cloning into '/build/tmp.UZdw0uapal/dist-newstyle/src/canonical_-1f90751276f12f5a'...
-  fatal: unable to access 'http://github.com/well-typed/canonical-json/': Could not resolve host: github.com
-[1 built (1 failed), 0.0 MiB DL]
-error: build of '/nix/store/g5023y5h06iy1bj076zzaaza0v8c80w3-plan-to-nix-pkgs.
-```
-
-Out of curiosity, I tried to disable the sandbox to see whether the build would succeed without it:
-
-```
-nix build -f . dummy-app.components.exes.dummy-app --option sandbox false
-trace: Using latest index state!
-trace: Using index-state: 2019-12-14T00:00:00Z
-builder for '/nix/store/g5023y5h06iy1bj076zzaaza0v8c80w3-plan-to-nix-pkgs.drv' failed with exit code 128; last 9 log lines:
-  Cloning into '/tmp/nix-build-plan-to-nix-pkgs.drv-0/tmp.GquFxkVGQR/dist-newstyle/src/canonical_-1f90751276f12f5a'...
-  warning: redirecting to https://github.com/well-typed/canonical-json/
-  remote: Enumerating objects: 4, done.
-  remote: Counting objects: 100% (4/4), done.
-  remote: Compressing objects: 100% (4/4), done.
-  remote: Total 130 (delta 0), reused 1 (delta 0), pack-reused 126
-  Receiving objects: 100% (130/130), 582.22 KiB | 1.43 MiB/s, done.
-  Resolving deltas: 100% (51/51), done.
-  fatal: invalid reference: ddfe3593b80b5ceb88842bb7a6f2268df75d2c2fpackages:
-[0 built (1 failed)]
-error: build of '/nix/store/g5023y5h06iy1bj076zzaaza0v8c80w3-plan-to-nix-pkgs.drv' failed
-(use '--show-trace' to show detailed location information)
-```
-
-Seems like something else is wrong here.
+- `nix build -f . dummy-app.components.exes.dummy-app` succeeds.
+- `cabal new-build` tries to fetch the `canonical` repo instead of
+  using the one cached in the `ghc-pkg` repo.
diff --git a/cabal.project b/cabal.project
index e5b4562..1e18276 100644
--- a/cabal.project
+++ b/cabal.project
@@ -7,4 +7,5 @@ package dummy-app
 source-repository-package
   type: git
   location: http://github.com/well-typed/canonical-json
-  tag: ddfe3593b80b5ceb88842bb7a6f2268df75d2c2f
\ No newline at end of file
+  tag: ddfe3593b80b5ceb88842bb7a6f2268df75d2c2f
+  --sha256: 02fzn1xskis1lc1pkz0j92v6ipd89ww0k2p3dvwpm3yap5dpnm7k
diff --git a/dummy-app/app/dummy-app.hs b/dummy-app/app/dummy-app.hs
index e9e1deb..377b6b5 100644
--- a/dummy-app/app/dummy-app.hs
+++ b/dummy-app/app/dummy-app.hs
@@ -1,2 +1,2 @@
 main :: IO ()
-main = undefined
+main = return ()
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..e9c836b
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,15 @@
+let
+  lib = import ./nix/lib.nix;
+  pkgs = lib.pkgs;
+  hsPkgs = import ./default.nix { };
+in
+hsPkgs.shellFor {
+  packages = ps: with ps; [
+    dummy-app
+  ];
+  withHoogle = true;
+  buildInputs = with pkgs.haskellPackages;
+    [ hlint stylish-haskell ghcid lib.niv lib.pkgs.haskell-nix.cabal-install ];
+  exactDeps = true;
+
+}