Try #1121:

builder/default.nix

@@ -26,8 +26,9 @@ let
   # component builder and for nix-shells.
   ghcForComponent = import ./ghc-for-component-wrapper.nix {
     inherit lib ghc haskellLib;
-    inherit (buildPackages) stdenv runCommand makeWrapper;
-    inherit (buildPackages.xorg) lndir;
+    inherit (buildPackages) stdenv;
+    inherit (pkgs.evalPackages) runCommand makeWrapper;
+    inherit (pkgs.evalPackages.xorg) lndir;
   };
 
   # Builds a derivation which contains a ghc package-db of

ci.nix

@@ -9,7 +9,6 @@
   inherit (import ./ci-lib.nix) dimension platformFilterGeneric filterAttrsOnlyRecursive;
   sources = import ./nix/sources.nix {};
   nixpkgsVersions = {
-    "R2003" = "nixpkgs-2003";
     "R2009" = "nixpkgs-2009";
     "unstable" = "nixpkgs-unstable";
   };
@@ -24,14 +23,14 @@
     # from here (so that is no longer cached) also remove ./materialized/ghcXXX.
     # Update supported-ghc-versions.md to reflect any changes made here.
     {
-      ghc865 = true;
+      ghc865 = false;
       ghc8104 = false; # Just included because the native version is needed at eval time
     } // nixpkgs.lib.optionalAttrs (nixpkgsName == "R2009") {
       ghc865 = false;
-      ghc884 = true;
       ghc8104 = true;
     } // nixpkgs.lib.optionalAttrs (nixpkgsName == "unstable") {
       ghc865 = false;
+      ghc884 = false; # Native version is used to boot 9.0.1
       ghc8104 = true;
       ghc901 = true;
       ghc810420210212 = false;
@@ -45,15 +44,13 @@
     # 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 == "unstable" && (__elem compiler-nix-name ["ghc865" "ghc884" "ghc8104"])) {
+    in lib.optionalAttrs (nixpkgsName == "unstable" && (__elem compiler-nix-name ["ghc8104"])) {
     inherit (lib.systems.examples) ghcjs;
-  } // lib.optionalAttrs (system == "x86_64-linux" && (
-         (nixpkgsName == "R2009" && __elem compiler-nix-name ["ghc8101" "ghc8102" "ghc8103" "ghc8104" "ghc810420210212"])
-      || (nixpkgsName == "R2003" && __elem compiler-nix-name ["ghc865"]))) {
+  } // lib.optionalAttrs (system == "x86_64-linux" &&
+         nixpkgsName == "unstable" && (__elem compiler-nix-name ["ghc8101" "ghc8102" "ghc8103" "ghc8104"])) {
     # Windows cross compilation is currently broken on macOS
     inherit (lib.systems.examples) mingwW64;
-  } // lib.optionalAttrs (system == "x86_64-linux"
-      && !(nixpkgsName == "R2003" && compiler-nix-name == "ghc8104")) {
+  } // lib.optionalAttrs (system == "x86_64-linux" && nixpkgsName == "unstable" && compiler-nix-name == "ghc8104") {
     # Musl cross only works on linux
     # aarch64 cross only works on linux
     # We also skip these for the R2003 was build of ghc8104 (we only need the

lib/ghcjs-project.nix

@@ -115,6 +115,8 @@ let
         cp ${../overlays/patches/config.sub} ghc/libraries/base/config.sub
         cp ${../overlays/patches/config.sub} ghc/libraries/unix/config.sub
 
+        sed -i 's/_AC_PROG_CC_C99/AC_PROG_CC_C99/' ghc/aclocal.m4
+
         patchShebangs .
         sed -i 's/gcc /cc /g' utils/makePackages.sh
         ./utils/makePackages.sh copy

nix/sources.json

@@ -149,10 +149,10 @@
         "homepage": "",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "410bbd828cdc6156aecd5bc91772ad3a6b1099c7",
-        "sha256": "0idvgvpgnzvk03yvd77lrca9qib936fq2x690jvk5gk3blsckz3r",
+        "rev": "d8eb97e3801bde96491535f40483d550b57605b9",
+        "sha256": "1bdd7jinq5d40qai45jfkbcw1n96c7fdlams5iidwzy2ag8axlqh",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/410bbd828cdc6156aecd5bc91772ad3a6b1099c7.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/d8eb97e3801bde96491535f40483d550b57605b9.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "old-ghc-nix": {

overlays/bootstrap.nix

@@ -160,6 +160,8 @@ in {
                 ++ final.lib.optional (versionAtLeast "8.10.4" && final.targetPlatform.isWindows) ./patches/ghc/ghc-8.10-z-drive-fix.patch
                 ++ final.lib.optional (versionAtLeast "8.6.5") ./patches/ghc/ghc-8.10-windows-add-dependent-file.patch
                 ++ fromUntil "8.10.1" "9.0"    ./patches/ghc/Cabal-unbreak-GHCJS.patch
+                ++ until              "8.10.5" ./patches/ghc/AC_PROG_CC_99.patch
+                ++ fromUntil "9.0.1"  "9.0.2" ./patches/ghc/AC_PROG_CC_99.patch
                 ;
         in ({
             ghc844 = final.callPackage ../compiler/ghc {
@@ -697,10 +699,10 @@ in {
           final.buildPackages.buildPackages.gitMinimal
           final.buildPackages.buildPackages.nix-prefetch-git ];
     in
-      final.symlinkJoin {
+      final.evalPackages.symlinkJoin {
         name = "nix-tools";
         paths = exes;
-        buildInputs = [ final.makeWrapper ];
+        buildInputs = [ final.evalPackages.makeWrapper ];
         meta.platforms = final.lib.platforms.all;
         # We wrap the -to-nix executables with the executables from `tools` (e.g. nix-prefetch-git)
         # so that consumers of `nix-tools` won't have to provide those tools.

overlays/patches/ghc/AC_PROG_CC_99.patch

@@ -0,0 +1,13 @@
+diff --git a/aclocal.m4 b/aclocal.m4
+index 259db63dbff84c91934100a0cb8ff19a0562e90f..99f77d910cfc2421acf3a7d9ac123d79d6daa2ff 100644
+--- a/aclocal.m4
++++ b/aclocal.m4
+@@ -659,7 +659,7 @@ AC_DEFUN([FP_SET_CFLAGS_C99],
+     CPPFLAGS="$$3"
+     unset ac_cv_prog_cc_c99
+     dnl perform detection
+-    _AC_PROG_CC_C99
++    AC_PROG_CC_C99
+     fp_cc_c99="$ac_cv_prog_cc_c99"
+     case "x$ac_cv_prog_cc_c99" in
+       x)   ;; # noop

release.nix

@@ -1,7 +1,7 @@
 # 'supportedSystems' restricts the set of systems that we will evaluate for. Useful when you're evaluating
 # on a machine with e.g. no way to build the Darwin IFDs you need!
 { supportedSystems ? [ "x86_64-linux" "x86_64-darwin" ]
-, ifdLevel ? 3
+, ifdLevel ? 1
 , checkMaterialization ? false }:
 
 let