diff --git a/recipes-devtools/cctools-port/cctools-port-crosssdk_1010.6.bb b/recipes-devtools/cctools-port/cctools-port-crosssdk_1010.6.bb
index 3abeb02..dcd5d01 100644
--- a/recipes-devtools/cctools-port/cctools-port-crosssdk_1010.6.bb
+++ b/recipes-devtools/cctools-port/cctools-port-crosssdk_1010.6.bb
@@ -23,9 +23,17 @@ DEPENDS += " \
     libcxx-native \
 "
 
-TOOLCHAIN:class-crosssdk = "clang"
-COMPILER_RT:class-crosssdk = "-rtlib=libgcc --unwindlib=libgcc"
-LIBCPLUSPLUS:class-crosssdk = "-stdlib=libc++ -lc++abi"
+# Selects clang for the native build; TOOLCHAIN:class-crosssdk has no effect here.
+# -stdlib=libc++ isn't added automatically, so this is C++ and needs it set directly.
+TOOLCHAIN_NATIVE = "clang"
+CXXFLAGS:append:class-crosssdk = " -stdlib=libc++"
+LDFLAGS:append:class-crosssdk = " -stdlib=libc++"
+
+# cctools' own include/stuff/bool.h declares "enum bool { FALSE, TRUE };",
+# which is a hard syntax error under C23, where bool is a reserved keyword
+# rather than a macro. Pin the C dialect to a pre-C23 standard rather than
+# relying on clang's default (gnu23 as of this clang version).
+CFLAGS:append:class-crosssdk = " -std=gnu17"
 
 EXTRA_OECONF:append = " \
     --with-llvm-config=${STAGING_DIR_NATIVE}/usr/bin/llvm-config \
diff --git a/recipes-devtools/libdispatch/libdispatch-native_git.bb b/recipes-devtools/libdispatch/libdispatch-native_git.bb
index c7dadd0..a3a1b2e 100644
--- a/recipes-devtools/libdispatch/libdispatch-native_git.bb
+++ b/recipes-devtools/libdispatch/libdispatch-native_git.bb
@@ -19,4 +19,11 @@ DEPENDS += " \
 "
 
 TC_CXX_RUNTIME:class-native = "llvm"
-TOOLCHAIN:class-native = "clang"
+
+# Selects clang for the native build; TOOLCHAIN:class-native has no effect here.
+TOOLCHAIN_NATIVE = "clang"
+
+# src/event/event_epoll.c (the Linux epoll port) hits a benign sign-conversion
+# warning on a plain bitmask op; upstream's own -Werror -Wsign-conversion
+# combo doesn't exempt it.
+CFLAGS:append:class-native = " -Wno-error=sign-conversion"
diff --git a/recipes-devtools/libtapi/libtapi-native_1300.6.5.bb b/recipes-devtools/libtapi/libtapi-native_1300.6.5.bb
index 5442f39..545aa59 100644
--- a/recipes-devtools/libtapi/libtapi-native_1300.6.5.bb
+++ b/recipes-devtools/libtapi/libtapi-native_1300.6.5.bb
@@ -24,9 +24,11 @@ DEPENDS += " \
     libcxx-native \
 "
 
-TOOLCHAIN:class-native = "clang"
-COMPILER_RT:class-native = "-rtlib=libgcc --unwindlib=libgcc"
-LIBCPLUSPLUS:class-native = "-stdlib=libc++ -lc++abi"
+# Selects clang for the native build; TOOLCHAIN:class-native has no effect here.
+# -stdlib=libc++ isn't added automatically, so this is C++ and needs it set directly.
+TOOLCHAIN_NATIVE = "clang"
+CXXFLAGS:append:class-native = " -stdlib=libc++"
+LDFLAGS:append:class-native = " -stdlib=libc++"
 
 CXXFLAGS += " \
     -I${S}/projects/clang/include \