Fix the way ExeDependency is handled (#1036)

See input-output-hk/nix-tools#101

We should look up hsPkgs.${pkg-name}.components.exe.${component-name}
instead of including the package as a dependency.

Adding `hsPkgs.${pkg-name}` a tool it is not clear which executable in the package `haskell.nix` should choose.

Haskell.nix did not deal with this well and in fact it could lead to `nix-shell` crashing.  For instance using `shellFor` to make a shell for building `haskell-language-server` with `cabal build` crashed as a dependency on `ghcide` the executable (by the `ghcide-bench` executable) caused infinite recursion.  Allowing `ghcide-bench` to correctly depend just on `components.exes.ghcide` fixes this.

This PR also includes:

* Updated materialized files built with the new nix-tools and latest index-state
* Small update to GHCJS (pins happy) to fix issue that showed up when the materialization was updated
* A fix for the infinite recursion issue when updating materialized files (by adding ghc-boot-packages-unchecked).
* Performance fix for shellFor (checks just the names of component derivations when filtering).

Author: hamishmack

builder/shell-for.nix

@@ -59,8 +59,8 @@ let
   # Given a list of derivations, removes those which are components of packages which were selected as part of the shell.
   removeSelectedInputs =
     # All the components of the selected packages: we shouldn't add any of these as dependencies
-    let selectedPackageComponents = lib.concatMap haskellLib.getAllComponents selectedPackages;
-    in lib.filter (input: !(builtins.elem input selectedPackageComponents));
+    let selectedPackageComponents = map (x: x.name) (lib.concatMap haskellLib.getAllComponents selectedPackages);
+    in lib.filter (input: !(builtins.elem input.name selectedPackageComponents));
 
   # We need to remove any dependencies which are selected packages (see above).
   # `depends` contains packages so we use 'removeSelectedPackages`.

ci.nix

@@ -43,7 +43,7 @@
     # We need to use the actual nixpkgs version we're working with here, since the values
     # of 'lib.systems.examples' are not understood between all versions
     let lib = nixpkgs.lib;
-    in lib.optionalAttrs (nixpkgsName == "R2009" && (__elem compiler-nix-name ["ghc865" "ghc884"])) {
+    in lib.optionalAttrs (nixpkgsName == "unstable" && (__elem compiler-nix-name ["ghc865" "ghc884"])) {
     inherit (lib.systems.examples) ghcjs;
   } // lib.optionalAttrs (system == "x86_64-linux" && (
          (nixpkgsName == "R2009" && __elem compiler-nix-name ["ghc8101" "ghc8102" "ghc8103" "ghc8104" "ghc810220201118"])

compiler/ghcjs/ghcjs88-src.json

@@ -1,6 +1,6 @@
 {
   "url": "https://github.com/ghcjs/ghcjs",
-  "rev": "1193ead2c760bab1e2ab461458ec771237ccf9b5",
-  "sha256": "1h7gaq1lhf61b5x693phgpm2z0w393b1sbkxrd9mxzz9xxlyrhkl",
+  "rev": "23e75593937dc15eaee73bed1443450fc68bd277",
+  "sha256": "1cj4q2rx3xs8zfkpjjwfdfadidg0wgn3qisffiikxmgf41b4a760",
   "fetchSubmodules": true
 }

lib/materialize.nix

@@ -56,7 +56,14 @@ let
         builtins.trace sha256message (builtins.trace materializeMessage calculateNoHash);
 
   # Build fully and check the hash and materialized versions
-  checked = runCommand name {} (''
+  checked =
+    # Let the user know what we are checking.  This is useful for debugging issues
+    # where materialization fails to prevent infinite recurstion when:
+    #   checkMaterialization = true;
+    (if materialized != null
+      then __trace "Checking materialization in ${toString materialized}"
+      else x: x)
+    runCommand name {} (''
         ERR=$(mktemp -d)/errors.txt
       ''
     + (pkgs.lib.optionalString (sha256 != null) ''