fix: set pixi cache dir when building cmake extensions (#4567)

Author: nichmor

crates/pixi/tests/integration_rust/install_tests.rs

@@ -805,7 +805,17 @@ setup(
         .contains(&"my-pkg".parse().unwrap());
 
     assert!(has_pkg, "my-pkg is not in no-build-isolation list");
-    pixi.install().await.expect("cannot install project");
+
+    let tmp_dir = tempdir().unwrap();
+    let tmp_dir_path = tmp_dir.path();
+
+    temp_env::async_with_vars(
+        [("PIXI_CACHE_DIR", Some(tmp_dir_path.to_str().unwrap()))],
+        async {
+            pixi.install().await.expect("cannot install project");
+        },
+    )
+    .await;
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
@@ -917,9 +927,19 @@ setup(
     // 2. PyPI packages with build isolation (package-tdjager) - batch
     // 3. PyPI packages without build isolation (package-b) - one by one
     // The key test: package-b should be able to import package-tdjager during its build
-    pixi.install()
-        .await
-        .expect("cannot install project with no-build-isolation dependencies");
+
+    let tmp_dir = tempdir().unwrap();
+    let tmp_dir_path = tmp_dir.path();
+
+    temp_env::async_with_vars(
+        [("PIXI_CACHE_DIR", Some(tmp_dir_path.to_str().unwrap()))],
+        async {
+            pixi.install()
+                .await
+                .expect("cannot install project with no-build-isolation dependencies");
+        },
+    )
+    .await;
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
@@ -953,7 +973,17 @@ async fn test_setuptools_override_failure() {
         platform = Platform::current()
     );
     let pixi = PixiControl::from_manifest(&manifest).expect("cannot instantiate pixi project");
-    pixi.install().await.expect("cannot install project");
+
+    let tmp_dir = tempdir().unwrap();
+    let tmp_dir_path = tmp_dir.path();
+
+    temp_env::async_with_vars(
+        [("PIXI_CACHE_DIR", Some(tmp_dir_path.to_str().unwrap()))],
+        async {
+            pixi.install().await.expect("cannot install project");
+        },
+    )
+    .await;
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 1)]

crates/pixi/tests/integration_rust/pypi_tests.rs

@@ -1,6 +1,7 @@
 use std::io::Write;
 
 use rattler_conda_types::Platform;
+use tempfile::tempdir;
 use typed_path::Utf8TypedPath;
 
 use crate::common::pypi_index::{Database as PyPIDatabase, PyPIPackage};
@@ -385,7 +386,17 @@ async fn test_indexes_are_passed_when_solving_build_pypi_dependencies() {
     let lock_file = pixi.update_lock_file().await.unwrap();
 
     // verify that the pypi-build-index can be installed when solved the build dependencies
-    pixi.install().await.unwrap();
+
+    let tmp_dir = tempdir().unwrap();
+    let tmp_dir_path = tmp_dir.path();
+
+    temp_env::async_with_vars(
+        [("PIXI_CACHE_DIR", Some(tmp_dir_path.to_str().unwrap()))],
+        async {
+            pixi.install().await.unwrap();
+        },
+    )
+    .await;
 
     let mut local_pypi_index = simple.index_path().display().to_string();