add initial vital-synth derivation

derivations/vital-synth/default.nix

@@ -0,0 +1,102 @@
+{ stdenv , fetchurl, alsa-lib, freetype, glib, glibc, libcurl-gnutls, libgl, libglvnd, libsecret }:
+
+# Adapted from https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=vital-synth
+# Example https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/audio/bitwig-studio/bitwig-studio4.nix
+
+let
+  # Variables from AUR pkgbuild
+  maintainer = "jackreeds";
+  pkgname_deb = "VitalInstaller";
+
+in stdenv.mkDerivation rec {
+  pname = "vital-synth";
+  version = "1.0.8";
+
+  src = fetchurl {
+    url = "https://github.com/${maintainer}/${pkgname_deb}/releases/download/${version}/${pkgname_deb}.deb";
+    sha512 = "829d29a0c41ac9f79ca6d069e2e4f404a501abdcdc487fbb4e1e8afd44bf870c6c41095587c98f810fb946d946179468f8d5f417e67785313152a1613cf4a832";
+  };
+
+  # - wrapGAppsHook will add the applications share directory to XDG_DATA_DIRS
+  #   It is also used to populate many environment variables related to icon themes etc.
+  # - makeWrapper allows to add environment variables and other stuff to the application, like a closure
+  # TODO: Is wrapGAppsHook needed?
+  nativeBuildInputs = [ dpkg makeWrapper wrapGAppsHook ];
+
+  # We downloaded a .deb file, unpack it to root = [ usr/bin usr/lib usr/share ]
+  unpackCmd = ''
+    mkdir -p root
+    dpkg-deb -x $curSrc root
+  '';
+
+  dontBuild = true;
+  dontWrapGApps = true; # we only want $gappsWrapperArgs here
+
+  # From AUR pkgbuild:
+  # depends=('alsa-lib>=1.0.16' 'freetype2>=2.2.1' 'gcc-libs' 'gcc>=3.3.1' 'glib2>=2.12.0' 'glibc>=2.17'
+  #          'libcurl-gnutls>=7.16.2' 'libgl' 'libglvnd' 'libsecret>=0.7')
+  # TODO: Verify every single dependency
+  buildInputs = [
+    alsa-lib freetype glib glibc libcurl-gnutls libgl libglvnd libsecret stdenv.cc.cc.lib
+  ];
+
+  # Copy the contents of the .deb package to the $out directory that nix creates for built derivations
+  # Very simple as the vital .deb has a very basic format (only [ usr/bin usr/lib usr/share ])
+  installPhase = ''
+    runHook preInstall
+
+    cp -r usr/* $out/
+    chmod +x $out/bin/vital
+
+    runHook postInstall
+  '';
+  # This was also in the bitwig-studio example but I don't think it is needed as the .desktop
+  # file doesn't contain absolute paths to the executable.
+  # Also it probably requires that the .desktop file isn't already in $out/share/applications,
+  # but I copied it there already by copying all the contents from usr/
+  # substitute usr/share/applications/vital.desktop \
+  #   $out/share/applications/vital.desktop \
+  #   --replace /usr/bin/vital $out/bin/vital
+
+  # This is taken from the bitwig-studio example and I don't fully understand it...
+  # Basically the output path is searched for executables, these are then pached/linked with the
+  # needed libraries. These libraries are then provided through the LD_LIBRARY_PATH
+  postFixup = ''
+    # Find all executables that should be patched
+    find $out -type f -executable \
+      -not -name '*.so.*' \
+      -not -name '*.so' \
+
+    while IFS= read -r f ; do
+      # I don't exactly understand this, have to read up on patchelf
+      patchelf --set-interpreter "${stdenv.cc.bintools.dynamicLinker}" $f
+
+      wrapProgram $f \
+        # I don't know what this does
+        "''${gappsWrapperArgs[@]}" \
+
+        # I don't know what binaries are needed for vital, probably not these
+        # --prefix PATH : "${lib.makeBinPath [ xdg-utils ffmpeg ]}" \
+
+        # We build the library path from our enabled buildInputs
+        --suffix LD_LIBRARY_PATH : "${lib.strings.makeLibraryPath buildInputs}"
+    done
+  '';
+  # This is specific for bitwig-studio derivation
+  # find $out -type f -executable -name 'jspawnhelper' | \
+  # while IFS= read -r f ; do
+  #   patchelf --set-interpreter "${stdenv.cc.bintools.dynamicLinker}" $f
+  # done
+
+  meta = with lib; {
+    description = "A wavetable synthesizer.";
+    longDescription = ''
+      Powerful wavetable synthesizer with realtime modulation feedback.
+      Vital is a MIDI enabled polyphonic music synthesizer with an easy to use
+      parameter modulation system with real-time graphical feedback.
+    '';
+    homepage = "https://vital.audio/";
+    license = licenses.gpl3Only;
+    platforms = [ "x86_64-linux" ];
+  };
+}