1 files changed, 80 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/development/interpreters/octave/build-env.nix b/nixpkgs/pkgs/development/interpreters/octave/build-env.nix
new file mode 100644
index 000000000000..433026f0a7e9
--- /dev/null
+++ b/nixpkgs/pkgs/development/interpreters/octave/build-env.nix
@@ -0,0 +1,80 @@
+{ lib, stdenv, octave, buildEnv
+, makeWrapper, texinfo
+, octavePackages
+, wrapOctave
+, computeRequiredOctavePackages
+, extraLibs ? []
+, extraOutputsToInstall ? []
+, postBuild ? ""
+, ignoreCollisions ? false
+}:
+
+# Create an octave executable that knows about additional packages
+let
+  packages = computeRequiredOctavePackages extraLibs;
+
+in buildEnv {
+  name = "${octave.name}-env";
+  paths = extraLibs ++ [ octave ];
+
+  inherit ignoreCollisions;
+  extraOutputsToInstall = [ "out" ] ++ extraOutputsToInstall;
+
+  nativeBuildInputs = [ makeWrapper ];
+  buildInputs = [ texinfo wrapOctave ];
+
+  # During "build" we must first unlink the /share symlink to octave's /share
+  # Then, we can re-symlink the all of octave/share, except for /share/octave
+  # in env/share/octave, re-symlink everything from octave/share/octave and then
+  # perform the pkg install.
+  postBuild = ''
+      if [ -L "$out/bin" ]; then
+         unlink $out/bin
+         mkdir -p "$out/bin"
+         cd "${octave}/bin"
+         for prg in *; do
+             if [ -x $prg ]; then
+                makeWrapper "${octave}/bin/$prg" "$out/bin/$prg" --set OCTAVE_SITE_INITFILE "$out/share/octave/site/m/startup/octaverc"
+             fi
+         done
+         cd $out
+      fi
+
+      # Remove symlinks to the input tarballs, they aren't needed.
+      rm $out/*.tar.gz
+
+      createOctavePackagesPath $out ${octave}
+
+      for path in ${lib.concatStringsSep " " packages}; do
+          if [ -e $path/*.tar.gz ]; then
+             $out/bin/octave-cli --eval "pkg local_list $out/.octave_packages; \
+                                         pkg prefix $out/${octave.octPkgsPath} $out/${octave.octPkgsPath}; \
+                                         pfx = pkg (\"prefix\"); \
+                                         pkg install -nodeps -local $path/*.tar.gz"
+          fi
+      done
+
+      # Re-write the octave-wide startup file (share/octave/site/m/startup/octaverc)
+      # To point to the new local_list in $out
+      addPkgLocalList $out ${octave}
+
+      wrapOctavePrograms "${lib.concatStringsSep " " packages}"
+     '' + postBuild;
+
+  inherit (octave) meta;
+
+  passthru = octave.passthru // {
+    interpreter = "$out/bin/octave";
+    inherit octave;
+    env = stdenv.mkDerivation {
+      name = "interactive-${octave.name}-environment";
+
+      buildCommand = ''
+        echo >&2 ""
+        echo >&2 "*** octave 'env' attributes are intended for interactive nix-shell sessions, not for building! ***"
+        echo >&2 ""
+        exit 1
+      '';
+    };
+  };
+}