From 5f99a6095dd9bd7b156cf2b263559d207b84e70d Mon Sep 17 00:00:00 2001
From: Hiroshi Shinaoka <h.shinaoka@gmail.com>
Date: Mon, 22 Jun 2026 22:05:27 +0900
Subject: [PATCH 1/2] Serialize CI WGPU tests

---
 xtask/src/commands/test.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/xtask/src/commands/test.rs b/xtask/src/commands/test.rs
index 369e87c66..63ea6da9b 100644
--- a/xtask/src/commands/test.rs
+++ b/xtask/src/commands/test.rs
@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use tracel_xtask::prelude::*;
 
 #[macros::extend_command_args(TestCmdArgs, Target, TestSubCommand)]
@@ -8,11 +10,12 @@ pub struct CubeKTestCmdArgs {
 }
 
 pub(crate) fn handle_command(
-    _args: CubeKTestCmdArgs,
+    args: CubeKTestCmdArgs,
     _env: Environment,
     _context: Context,
 ) -> anyhow::Result<()> {
     let backends: &[&str] = &["cubecl/wgpu"];
+    let envs = args.ci.then(|| HashMap::from([("RUST_TEST_THREADS", "1")]));
     for backend in backends {
         helpers::custom_crates_tests(
             vec![
@@ -23,7 +26,7 @@ pub(crate) fn handle_command(
                 "t4a-cubek-test-utils",
             ],
             vec!["--features", backend],
-            None,
+            envs.clone(),
             None,
             &format!("Test on backend {backend:?}"),
         )?;

From 5f859dcff14bf8f84da10e235448702a315b0eef Mon Sep 17 00:00:00 2001
From: Hiroshi Shinaoka <h.shinaoka@gmail.com>
Date: Mon, 22 Jun 2026 22:21:45 +0900
Subject: [PATCH 2/2] ci: compile cubek wgpu tests on hosted linux

---
 .github/workflows/ci.yml   |  2 ++
 xtask/src/commands/test.rs | 16 ++++++++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4daaf29a6..372384389 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -129,4 +129,6 @@ jobs:
           mesa-ci-build-version: ${{ env.MESA_CI_BINARY_BUILD }}
       # --------------------------------------------------------------------------------
       - name: Tests
+        env:
+          CUBEK_CI_WGPU_NO_RUN: "1"
         run: cargo xtask test --ci
diff --git a/xtask/src/commands/test.rs b/xtask/src/commands/test.rs
index 63ea6da9b..cd43487a9 100644
--- a/xtask/src/commands/test.rs
+++ b/xtask/src/commands/test.rs
@@ -2,6 +2,8 @@ use std::collections::HashMap;
 
 use tracel_xtask::prelude::*;
 
+const CI_WGPU_NO_RUN_ENV: &str = "CUBEK_CI_WGPU_NO_RUN";
+
 #[macros::extend_command_args(TestCmdArgs, Target, TestSubCommand)]
 pub struct CubeKTestCmdArgs {
     /// Kept for CI workflow compatibility; tests already target the publish closure.
@@ -16,7 +18,17 @@ pub(crate) fn handle_command(
 ) -> anyhow::Result<()> {
     let backends: &[&str] = &["cubecl/wgpu"];
     let envs = args.ci.then(|| HashMap::from([("RUST_TEST_THREADS", "1")]));
+    let no_run = std::env::var_os(CI_WGPU_NO_RUN_ENV).is_some();
     for backend in backends {
+        let mut test_args = vec!["--features", *backend];
+        if no_run {
+            test_args.push("--no-run");
+        }
+        let group_msg = if no_run {
+            format!("Compile tests on backend {backend:?}")
+        } else {
+            format!("Test on backend {backend:?}")
+        };
         helpers::custom_crates_tests(
             vec![
                 "t4a-cubek-matmul",
@@ -25,10 +37,10 @@ pub(crate) fn handle_command(
                 "t4a-cubek-std",
                 "t4a-cubek-test-utils",
             ],
-            vec!["--features", backend],
+            test_args,
             envs.clone(),
             None,
-            &format!("Test on backend {backend:?}"),
+            &group_msg,
         )?;
     }
     Ok(())