move nix-tools logic to nix/haskell-packages

Avoids infinite recursion with release.nix including byronProxyScripts

default.nix

@@ -1,6 +1,5 @@
-{ ... }@args:
 #
-# The defaul.nix file. This will generate targets for all
+# The default.nix file. This will generate targets for all
 # buildables (see release.nix for nomenclature, excluding
 # the "build machine" last part, specific to release.nix), eg.:
 #
@@ -27,29 +26,22 @@
 # https://github.com/input-output-hk/iohk-nix/blob/master/docs/nix-toolification.org#for-a-stackage-project
 #
 
-# We will need to import the iohk-nix common lib, which includes
-# the nix-tools tooling.
 let
   commonLib = import ./nix/iohk-common.nix;
 
-# This file needs to export a function that takes
-# the arguments it is passed and forwards them to
-# the default-nix template from iohk-nix. This is
-# important so that the release.nix file can properly
-# parameterize this file when targetting different
-# hosts.
-  nixTools = commonLib.nix-tools.default-nix ./nix/pkgs.nix args;
+  # Haskell Packages produced by nix-tools
+  haskellPackages = import ./nix/haskell-packages.nix {};
   # TODO: remove when proxy and old cardano configs no
   # longer required.
   oldCardanoSrc = import ./nix/old-cardano.nix {
     inherit commonLib;
   };
-  byronProxy = nixTools.nix-tools.exes.byron-proxy;
+  byronProxy = haskellPackages.nix-tools.exes.byron-proxy;
   # TODO: move scripts to cardano-shell at some point.
   byronProxyScripts = import ./nix/byron-proxy-scripts.nix {
     inherit commonLib oldCardanoSrc byronProxy;
   };
 in {
   inherit byronProxyScripts commonLib;
-  inherit (nixTools) nix-tools;
+  inherit (haskellPackages) nix-tools;
 }

nix/haskell-packages.nix

@@ -0,0 +1,48 @@
+#
+# The defaul.nix file. This will generate targets for all
+# buildables (see release.nix for nomenclature, excluding
+# the "build machine" last part, specific to release.nix), eg.:
+#
+# - nix build -f default.nix nix-tools.tests.io-sim # All `io-sim` tests
+# - nix build -f default.nix nix-tools.tests.ouroboros-consensus.test-consensus
+#
+# Generated targets include anything from stack.yaml (via
+# nix-tools:stack-to-nix and the nix/regenerate.sh script)
+# or cabal.project (via nix-tools:plan-to-nix), including all
+# version overrides specified there.
+#
+# Nix-tools stack-to-nix will generate the `nix/.stack-pkgs.nix`
+# file which is imported from the `nix/pkgs.nix` where further
+# customizations outside of the ones in stack.yaml/cabal.project
+# can be specified as needed for nix/ci.
+#
+# Please run `nix/regenerate.sh` after modifying stack.yaml
+# or relevant part of cabal configuration files.
+# When switching to recent stackage or hackage package version,
+# you might also need to update the iohk-nix common lib. You
+# can do so by running the `nix/update-iohk-nix.sh` script.
+#
+# More information about iohk-nix and nix-tools is available at:
+# https://github.com/input-output-hk/iohk-nix/blob/master/docs/nix-toolification.org#for-a-stackage-project
+#
+
+
+# We will need to import the iohk-nix common lib, which includes
+# the nix-tools tooling.
+let
+  commonLib = import ./nix/iohk-common.nix;
+in
+# This file needs to export a function that takes
+# the arguments it is passed and forwards them to
+# the default-nix template from iohk-nix. This is
+# important so that the release.nix file can properly
+# parameterize this file when targetting different
+# hosts.
+{ ... }@args:
+# We will instantiate the default-nix template with the
+# nix/pkgs.nix file...
+commonLib.nix-tools.default-nix ./nix/pkgs.nix args
+# ... and add additional non-haskell packages we want to build on CI:
+// {
+
+}

release.nix

@@ -11,7 +11,7 @@ commonLib.pkgs.lib.mapAttrsRecursiveCond
 (as: !(as ? "type" && as.type == "derivation"))
 (path: v: if (builtins.elem path disabled) then null else v)
 (commonLib.nix-tools.release-nix {
-  package-set-path = ./.;
+  package-set-path = ./nix/haskell-packages.nix;
 
   # packages from our stack.yaml or plan file (via nix/pkgs.nix) we
   # are interested in building on CI via nix-tools.