octavePackages.windows: Run autoreconf hook on compiled sources

These sources include leftover config.guess and config.sub scripts
generated by upstream maintainer's bootstrap script. Their bootstrap
script uses wget to grab config.guess and config.sub files, which we
cannot do inside the Nix build environment. So we forcibly remove the
config.* scripts and run autoreconf ourselves (through
autoreconfHook).

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

@@ -3,6 +3,7 @@
   lib,
   fetchFromGitHub,
   nix-update-script,
+  autoreconfHook,
 }:
 
 buildOctavePackage rec {
@@ -16,6 +17,25 @@ buildOctavePackage rec {
     sha256 = "sha256-hr94VALlAEwpqNU7imEN63M0BdPFSu5IznhWOn/mNiQ=";
   };
 
+  nativeBuildInputs = [
+    autoreconfHook
+  ];
+
+  # 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
+  '';
+
   passthru.updateScript = nix-update-script { extraArgs = [ "--version-regex=release-(.*)" ]; };
 
   meta = {