nix: hack static-haskell-nix for updated nixpkgs

This patches static-haskell-nix to work for building postgrest
with updated nixpkgs (from ~202203):

- The ncurses 'enableStatic' argument doesn't exist anymore.
  We use the vanilla package instead, which seems to work fine.
- The 'isExecutable' check fails with a strange error related
  to trying to override 'mkDerivation'.
  We patch 'isExecutable' to check explicitly whether we're building
  postgrest. ('isExecutable' is used to determine whether to build
  a package statically.)

nix/patches/default.nix

@@ -21,4 +21,9 @@
   # See: https://github.com/NixOS/nixpkgs/pull/87879
   nixpkgs-openssl-split-runtime-dependencies-of-static-builds =
     ./nixpkgs-openssl-split-runtime-dependencies-of-static-builds.patch;
+
+  static-haskell-nix-ncurses =
+    ./static-haskell-nix-ncurses.patch;
+  static-haskell-nix-isexecutable =
+    ./static-haskell-nix-isexecutable.patch;
 }

nix/patches/static-haskell-nix-isexecutable.patch

@@ -0,0 +1,18 @@
+diff --git a/survey/default.nix b/survey/default.nix
+index 46d8066..5f7950b 100644
+--- a/survey/default.nix
++++ b/survey/default.nix
+@@ -85,10 +85,9 @@ let
+   # Function that tells us if a given Haskell package has an executable.
+   # Pass only Haskell packages to this!
+   # Filter away other stuff with `isProperHaskellPackage` first.
+-  isExecutable = pkg:
+-    (pkgs.haskell.lib.overrideCabal pkg (drv: {
+-      passthru.isExecutable = drv.isExecutable or false;
+-    })).isExecutable;
++  # FIXME postgrest: original fails with our nixpkgs version, we
++  # just hardcode the check to work for a static postgrest build.
++  isExecutable = pkg: pkg.name == "postgrest";
+
+   # Turn e.g. `Cabal_1_2_3_4` into `1.2.3.4`.
+   cabalDottedVersion =

nix/patches/static-haskell-nix-ncurses.patch

@@ -0,0 +1,13 @@
+diff --git a/survey/default.nix b/survey/default.nix
+index 46d8066..a47f214 100644
+--- a/survey/default.nix
++++ b/survey/default.nix
+@@ -1519,7 +1519,7 @@ let
+                   [
+                     "--enable-executable-static" # requires `useFixedCabal`
+                     # `enableShared` seems to be required to avoid `recompile with -fPIC` errors on some packages.
+-                    "--extra-lib-dirs=${final.ncurses.override { enableStatic = true; enableShared = true; }}/lib"
++                    "--extra-lib-dirs=${final.ncurses}/lib"
+                   ]
+                   # TODO Figure out why this and the below libffi are necessary.
+                   #      `working` and `workingStackageExecutables` don't seem to need that,

nix/static-haskell-package.nix

@@ -17,7 +17,8 @@ let
     patches.applyPatches "patched-static-haskell-nix"
       static-haskell-nix
       [
-        # No patches currently required.
+        patches.static-haskell-nix-ncurses
+        patches.static-haskell-nix-isexecutable
       ];
 
   patchedNixpkgs =