Build Linux x64 against an isolated sysroot.

crates/bds-ui/tests/packaging_assets.rs

@@ -193,38 +193,42 @@ fn tagged_releases_are_built_and_packaged_with_rust_tools() {
         "libwebkit2gtk-4.1-dev:amd64",
         "gcc-x86-64-linux-gnu",
         "Architectures: arm64",
-        "remove -y mercurial python3-importlib-metadata python3-jwt",
-        "install_packages python3 python3-typing-extensions",
+        "--download-only",
+        "dpkg-deb --extract",
+        "/opt/ruds-x64-sysroot",
     ] {
         assert!(
             linux_dependencies.contains(required),
             "Linux dependency setup is missing {required}"
         );
     }
-    let cleanup = linux_dependencies
-        .find("remove -y mercurial python3-importlib-metadata python3-jwt")
-        .expect("runner Python cleanup");
     let multiarch = linux_dependencies
         .find("dpkg --add-architecture amd64")
         .expect("amd64 architecture setup");
     assert!(
-        cleanup < multiarch,
-        "runner-only Python packages must be removed before enabling multiarch"
+        !linux_dependencies.contains("apt-get remove"),
+        "cross-build setup must not replace native runner packages"
     );
-    let native_python = linux_dependencies
-        .find("install_packages python3 python3-typing-extensions")
-        .expect("native Python dependency setup");
     let native_source_filter = linux_dependencies
         .find("'/^Architectures:/d; /^Types: deb$/a Architectures: arm64'")
         .expect("native apt architecture filter");
+    let native_cross_compiler = linux_dependencies
+        .find("install_packages build-essential cmake gcc-x86-64-linux-gnu")
+        .expect("native cross compiler setup");
     assert!(
-        linux_dependencies[native_source_filter..native_python].contains("sudo apt-get update"),
+        linux_dependencies[native_source_filter..native_cross_compiler]
+            .contains("sudo apt-get update"),
         "native apt indexes must be refreshed after constraining the source architecture"
     );
     assert!(
-        native_python < multiarch,
-        "native Python dependencies must be fixed before enabling multiarch"
+        native_cross_compiler < multiarch,
+        "the native cross compiler must be installed before enabling multiarch"
     );
+    assert!(
+        linux_dependencies.find("--download-only").unwrap() > multiarch,
+        "foreign libraries must only be downloaded after enabling multiarch"
+    );
+    assert!(workflow.contains("PKG_CONFIG_SYSROOT_DIR: /opt/ruds-x64-sysroot"));
 
     let workspace_manifest = fs::read_to_string(workspace.join("Cargo.toml")).unwrap();
     let core_manifest = fs::read_to_string(workspace.join("crates/bds-core/Cargo.toml")).unwrap();