Use nixpkgs from flake.lock and support attrs when importing bscpkgs

This makes `nix-build` and friends use the current flake lock instead of
the outdated pinned version we had in `./nixpkgs.nix`

With this, `nix-build -A ovni` and `nix build .#ovni` will produce the
same result.

This will fail if the flake nixpkgs input does not come from NixOS/nixpkgs.
We could use edolstra/flake-compat instead, but it's overkill imho.

Additionally, I made default.nix behave like nixpkgs, so that we can
import bscpkgs à la nixpkgs (Apply overlays and other options that nixpkgs
accepts): `import bscpkgs { overlays = [ <...> ]; }`

default.nix

@@ -1,11 +1,19 @@
 let
   bscOverlay = import ./overlay.nix;
 
-  # Pin the nixpkgs
-  nixpkgsPath = import ./nixpkgs.nix;
-
-  pkgs = import nixpkgsPath {
-    overlays = [ bscOverlay ];
+  # read flake.lock and determine revision from there
+  lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+  inherit (lock.nodes.nixpkgs.locked) rev narHash;
+  fetchedNixpkgs = builtins.fetchTarball {
+    url = "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
+    sha256 = narHash;
   };
-
-in pkgs
+in
+{ overlays ? [ ]
+, nixpkgs ? fetchedNixpkgs
+, ...
+}@attrs:
+import nixpkgs (
+  (builtins.removeAttrs attrs [ "overlays" "nixpkgs" ]) //
+  { overlays = [ bscOverlay ] ++ overlays; }
+)

flake.nix

@@ -13,5 +13,9 @@
       bscOverlay = import ./overlay.nix;
       overlays.default = self.bscOverlay;
       legacyPackages.x86_64-linux = pkgs;
+
+      hydraJobs = {
+        inherit (pkgs) bsc-ci;
+      };
     };
 }

nixpkgs.nix

@@ -1,9 +0,0 @@
-let
-  commit = "e4ad989506ec7d71f7302cc3067abd82730a4beb";
-in builtins.fetchTarball {
-    # Descriptive name to make the store path easier to identify
-    name = "nixpkgs-${commit}";
-    url = "https://github.com/nixos/nixpkgs/archive/${commit}.tar.gz";
-    # Hash obtained using `nix-prefetch-url --unpack <url>`
-    sha256 = "sha256-de9KYi8rSJpqvBfNwscWdalIJXPo8NjdIZcEJum1mH0=";
-}

overlay.nix

@@ -20,7 +20,6 @@ let
     #extrae = callPackage ./pkgs/extrae/default.nix { }; # Broken and outdated
     gpi-2 = callPackage ./pkgs/gpi-2/default.nix { };
     intelPackages_2023 = callPackage ./pkgs/intel-oneapi/2023.nix { };
-    intelPackages = final.intelPackages_2023;
     jemallocNanos6 = callPackage ./pkgs/nanos6/jemalloc.nix { };
     #lmbench = callPackage ./pkgs/lmbench/default.nix { }; # Broken
     mcxx = callPackage ./pkgs/mcxx/default.nix { };
@@ -61,7 +60,6 @@ in bscPkgs // {
       #sigsegv = callPackage ./test/reproducers/sigsegv.nix { };
       hello-c = callPackage ./test/compilers/hello-c.nix { };
       hello-cpp = callPackage ./test/compilers/hello-cpp.nix { };
-      hello-sycl = callPackage ./test/compilers/hello-sycl.nix { };
       lto = callPackage ./test/compilers/lto.nix { };
       asan = callPackage ./test/compilers/asan.nix { };
       intel2023-icx-c   = hello-c.override   { stdenv = final.intelPackages_2023.stdenv; };

pkgs/intel-oneapi/2023.nix

@@ -313,9 +313,6 @@ let
       "intel-oneapi-compiler-dpcpp-cpp-and-cpp-classic-common-${version}"
       "intel-oneapi-compiler-dpcpp-cpp-and-cpp-classic-runtime-${version}"
       "intel-oneapi-compiler-dpcpp-cpp-classic-fortran-shared-runtime-${version}"
-      "intel-oneapi-compiler-shared-${version}"
-      "intel-oneapi-compiler-shared-common-${version}"
-      "intel-oneapi-compiler-shared-runtime-${version}"
     ];
     # From https://aur.archlinux.org/packages/intel-oneapi-compiler:
     # - intel-oneapi-compiler-cpp-eclipse-cfg-2023.0.0-25370_all.deb
@@ -332,9 +329,9 @@ let
     # - intel-oneapi-compiler-fortran-common-2023.0.0-2023.0.0-25370_all.deb
     # - intel-oneapi-compiler-fortran-runtime-2023.0.0-2023.0.0-25370_amd64.deb
     # - intel-oneapi-compiler-fortran-runtime-2023.0.0-25370_amd64.deb
-    # + intel-oneapi-compiler-shared-2023.0.0-2023.0.0-25370_amd64.deb
-    # + intel-oneapi-compiler-shared-common-2023.0.0-2023.0.0-25370_all.deb
-    # + intel-oneapi-compiler-shared-runtime-2023.0.0-2023.0.0-25370_amd64.deb
+    # - intel-oneapi-compiler-shared-2023.0.0-2023.0.0-25370_amd64.deb
+    # - intel-oneapi-compiler-shared-common-2023.0.0-2023.0.0-25370_all.deb
+    # - intel-oneapi-compiler-shared-runtime-2023.0.0-2023.0.0-25370_amd64.deb
     # - intel-oneapi-dpcpp-cpp-2023.0.0-2023.0.0-25370_amd64.deb
     # - intel-oneapi-openmp-2023.0.0-2023.0.0-25370_amd64.deb
     # - intel-oneapi-openmp-common-2023.0.0-2023.0.0-25370_all.deb
@@ -401,15 +398,6 @@ let
         echo "-L${intel-compiler-shared}/lib" >> $out/nix-support/cc-ldflags
         echo "-L${cc}/lib" >> $out/nix-support/cc-ldflags
 
-        echo "--gcc-toolchain=${mygcc.cc}" >> $out/nix-support/libcxx-cxxflags
-
-        for dir in ${mygcc.cc}/include/c++/*; do
-          echo "-isystem $dir" >> $out/nix-support/libcxx-cxxflags
-        done
-        for dir in ${mygcc.cc}/include/c++/*/${targetConfig}; do
-          echo "-isystem $dir" >> $out/nix-support/libcxx-cxxflags
-        done
-
         # Need the gcc in the path
         echo 'export "PATH=${mygcc}/bin:$PATH"' >> $out/nix-support/cc-wrapper-hook
 

test/compilers/hello-sycl.nix

@@ -1,55 +0,0 @@
-{ intelPackages,  writeText, strace }:
-
-let
-  stdenv = intelPackages.stdenv;
-  hello_sycl = writeText "hello.cpp" ''
-    #include <sycl/sycl.hpp>
-
-    class hello_world;
-
-    int main(int argc, char** argv) try {
-        auto device_selector = sycl::default_selector_v;
-
-        sycl::queue queue(device_selector);
-
-        std::cout << "Running on: "
-                  << queue.get_device().get_info<sycl::info::device::name>()
-                  << std::endl;
-
-        queue.submit([&] (sycl::handler& cgh) {
-            auto os = sycl::stream{128, 128, cgh};
-            cgh.single_task<hello_world>([=]() {
-                os << "Hello World! (on device)\n";
-            });
-        });
-
-        return 0;
-    } catch (sycl::exception &e) {
-        std::cout << "SYCL exception: " << e.what() << std::endl;
-        return 0; // we excpect to fail since no devices should be available;
-    }
-  '';
-in
-
-stdenv.mkDerivation {
-  version = "0.0.1";
-  name = "hello-sycl";
-  buildInputs = [ stdenv strace ];
-  src = hello_sycl;
-  dontUnpack = true;
-  dontConfigure = true;
-  NIX_DEBUG = 0;
-  buildPhase = ''
-    cp $src hello.cpp
-    set -x
-    echo CXX=$CXX
-    command -v $CXX
-    $CXX -fsycl hello.cpp -o hello
-    ./hello
-    set +x
-  '';
-
-  installPhase = ''
-    touch $out
-  '';
-}