octavePackages.netcdf: Fix build & test, 1.0.19 -> 1.0.20 (#526460)

pkgs/development/octave-modules/netcdf/default.nix

@@ -4,23 +4,45 @@
   fetchFromGitHub,
   netcdf,
   nix-update-script,
+  pkg-config,
+  autoreconfHook,
 }:
 
 buildOctavePackage rec {
   pname = "netcdf";
-  version = "1.0.19";
+  version = "1.0.20";
 
   src = fetchFromGitHub {
     owner = "gnu-octave";
     repo = "octave-netcdf";
     tag = "v${version}";
-    sha256 = "sha256-yt39bd6EBLj7mr6EYngPfPXEMusncc9tx5So1Cp1zkM=";
+    sha256 = "sha256-47+8daOrPjjsVWi6Sz2V/GNK4vQ5nbGCrQmgnZRap+k=";
   };
 
+  nativeBuildInputs = [
+    pkg-config
+    autoreconfHook
+  ];
+
   propagatedBuildInputs = [
     netcdf
   ];
 
+  # autoreconfHook provides an autoreconfPhase that is run as a
+  # preconfigurePhase, which means it runs AFTER the source is un-tarred, and
+  # before buildOctavePackage's buildPhase re-tars it up into a format for later
+  # consumption by Octave's "pkg build" command.
+  preAutoreconf = ''
+    pushd src
+    # Upstream's bootstrap script uses wget to fetch config.guess & config.sub
+    # and has them committed to the repository. We must remove them so autoreconf
+    # actually fires for our environment.
+    rm config.*
+  '';
+  postAutoreconf = ''
+    popd
+  '';
+
   meta = {
     homepage = "https://gnu-octave.github.io/packages/netcdf/";
     license = lib.licenses.gpl2Plus;