This works on Linux with clang++-19

Author: ClausKlein

CMakeLists.txt

@@ -16,7 +16,9 @@ if(CMAKE_CXX_SCAN_FOR_MODULES)
             /usr/local/Cellar/gcc/15.2.0/lib/gcc/current/libstdc++.modules.json
         )
     else()
-        set(CMAKE_CXX_STDLIB_MODULES_JSON $ENV{LLVM_DIR}/lib/c++/libc++.modules.json)
+        set(CMAKE_CXX_STDLIB_MODULES_JSON
+            $ENV{LLVM_DIR}/lib/c++/libc++.modules.json
+        )
     endif()
 endif()
 

module/tests/CMakeLists.txt

@@ -21,7 +21,7 @@ if(PROJECT_IS_TOP_LEVEL)
     if(CMAKE_GENERATOR STREQUAL "Ninja")
         if(
             CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
-            AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 20.0
+            AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 19.0
         )
             set(USE_MODULES ON)
             # see https://releases.llvm.org/15.0.0/projects/libcxx/docs/ReleaseNotes.html