alacritty-ligatures: add runtime dependencies

Ones of the changes from 0.5.0 is depending on the system fontconfig,
and one of the ligature changes forces the use of the system freetype.

One of the Rust libraries depends on the C++ stdlib.

At some point the build process stopped bundling the OpenGL libraries,
so add those back in too.

.travis.yml

@@ -12,8 +12,8 @@ env:
 
 jobs:
   include:
-    - env: NIX_PATH=nixpkgs=channel:nixpkgs-unstable
+    # - env: NIX_PATH=nixpkgs=channel:nixpkgs-unstable
-    - env: NIX_PATH=nixpkgs=channel:nixos-unstable
+    # - env: NIX_PATH=nixpkgs=channel:nixos-unstable
     - env: NIX_PATH=nixpkgs=channel:nixos-20.03
 
 script:

default.nix

@@ -16,8 +16,8 @@ rec {
 
   # Alacritty with the unmerged ligature patches applied.
   alacritty-ligatures = (pkgs.alacritty.override {
-    # Requires a minimum of 1.41, and this is the only version on both stable
+    # 0.6.0 requires a minimum of 1.43, and this is the only version on both
-    # and unstable channels right now.
+    # stable and unstable channels right now.
     inherit (pkgs.rustPackages_1_44) rustPlatform;
   }).overrideAttrs (oldAttrs: rec {
     pname = "${oldAttrs.pname}-ligatures";
@@ -36,6 +36,24 @@ rec {
       inherit src;
       outputHash = "1zvj8hdlc3fii1ffwkigvxjigwx53vls543pgcv3a2bw4sn1ky1k";
     });
+
+    ligatureInputs = [
+      pkgs.fontconfig
+      pkgs.freetype
+      pkgs.libglvnd
+      pkgs.stdenv.cc.cc.lib
+      pkgs.xlibs.libxcb
+    ];
+
+    buildInputs = (oldAttrs.buildInputs or []) ++ ligatureInputs;
+
+    # HACK: One of the ligature libraries required the C++ stdlib at runtime,
+    # and I can't work out a better way to push it to the RPATH.
+    postInstall = pkgs.lib.optional (!pkgs.stdenv.isDarwin) ''
+      patchelf \
+        --set-rpath ${pkgs.lib.makeLibraryPath ligatureInputs}:"$(patchelf --show-rpath $out/bin/alacritty)" \
+        $out/bin/alacritty
+    '';
   });
 
   amdgpu-fan = pkgs.callPackage ./pkgs/tools/misc/amdgpu-fan { };