diff --git a/cmake/modules/kernel.cmake b/cmake/modules/kernel.cmake
index 7e65c9cd186..a093d46691f 100644
--- a/cmake/modules/kernel.cmake
+++ b/cmake/modules/kernel.cmake
@@ -142,7 +142,8 @@ enable_language(C CXX ASM)
 # Verify that the toolchain can compile a dummy file, if it is not we
 # won't be able to test for compatibility with certain C flags.
 zephyr_check_compiler_flag(C "" toolchain_is_ok)
-assert(toolchain_is_ok "The toolchain is unable to build a dummy C file. See CMakeError.log.")
+assert(toolchain_is_ok "The toolchain is unable to build a dummy C file.\
+ Move ${USER_CACHE_DIR}, re-run and look at CMakeError.log")
 
 include(${ZEPHYR_BASE}/cmake/target_toolchain_flags.cmake)