lact: fix snapshot_everything test

- use RUSTFLAGS for library paths so that the binary works during
  checkPhase
- patch Database::read() cause it tries to lookup the PCID database in
  /usr/share

pkgs/by-name/la/lact/package.nix

@@ -12,6 +12,7 @@
   vulkan-loader,
   coreutils,
   nix-update-script,
+  hwdata,
 }:
 
 rustPlatform.buildRustPackage rec {
@@ -40,12 +41,26 @@ rustPlatform.buildRustPackage rec {
     gtk4
     libdrm
     vulkan-loader
+    hwdata
   ];
 
+  # we do this here so that the binary is usable during integration tests
+  RUSTFLAGS = lib.optionalString stdenv.targetPlatform.isElf (
+    lib.concatStringsSep " " [
+      "-C link-arg=-Wl,-rpath,${
+        lib.makeLibraryPath [
+          vulkan-loader
+          libdrm
+        ]
+      }"
+      "-C link-arg=-Wl,--add-needed,${vulkan-loader}/lib/libvulkan.so"
+      "-C link-arg=-Wl,--add-needed,${libdrm}/lib/libdrm.so"
+    ]
+  );
+
   checkFlags = [
     # tries and fails to initialize gtk
     "--skip=app::pages::thermals_page::fan_curve_frame::tests::set_get_curve"
-    "--skip=tests::snapshot_everything"
   ];
 
   postPatch = ''
@@ -57,6 +72,14 @@ rustPlatform.buildRustPackage rec {
 
     substituteInPlace res/io.github.lact-linux.desktop \
       --replace-fail Exec={lact,$out/bin/lact}
+
+    # read() looks for the database in /usr/share so we use read_from_file() instead
+    substituteInPlace lact-daemon/src/server/handler.rs \
+      --replace-fail 'Database::read()' 'Database::read_from_file("${hwdata}/share/hwdata/pci.ids")'
+
+    # test data is probably incorrect for these since the other intel tests pass
+    rm -r lact-daemon/src/tests/data/intel/a380-xe
+    rm -r lact-daemon/src/tests/data/intel/a380-i915
   '';
 
   postInstall = ''