diff --git a/.github/workflows/libc-fullbuild-tests.yml b/.github/workflows/libc-fullbuild-tests.yml
index 24d75f58d45e0..c4b195dd82cab 100644
--- a/.github/workflows/libc-fullbuild-tests.yml
+++ b/.github/workflows/libc-fullbuild-tests.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        build_type: [Debug, Release, MinSizeRel]
+        # build_type: [Debug, Release, MinSizeRel]
         include:
           - os: ubuntu-24.04
             ccache-variant: sccache
diff --git a/.github/workflows/libc-overlay-tests.yml b/.github/workflows/libc-overlay-tests.yml
index da82d8d9fe8ab..a4958fbbeb58f 100644
--- a/.github/workflows/libc-overlay-tests.yml
+++ b/.github/workflows/libc-overlay-tests.yml
@@ -17,6 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         build_type: [Debug, Release, MinSizeRel]
+        os: [ubuntu-24.04, ubuntu-24.04-arm, windows-2022, windows-2025, macos-14]
         include:
           # TODO: add linux gcc when it is fixed
           - os: ubuntu-24.04
diff --git a/libc/CMakeLists.txt b/libc/CMakeLists.txt
index 507b3aa88babf..9197281e73099 100644
--- a/libc/CMakeLists.txt
+++ b/libc/CMakeLists.txt
@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 3.20.0)
 set(LLVM_SUBPROJECT_TITLE "libc")
 
+# nothing change
+
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   message(FATAL_ERROR "Builds rooted in the libc directory are not supported. "
     "Builds should be rooted in the runtimes directory instead. "
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
index a665253c4cc03..542c75db71853 100644
--- a/libc/src/CMakeLists.txt
+++ b/libc/src/CMakeLists.txt
@@ -19,6 +19,7 @@ add_subdirectory(unistd)
 add_subdirectory(wchar)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
+  message(FATAL_ERROR "hello world")
   add_subdirectory(dirent)
   add_subdirectory(fcntl)
   add_subdirectory(poll)