diff --git a/local/recipes/dev/llvm-native/recipe.toml b/local/recipes/dev/llvm-native/recipe.toml
index b356a3b39e..071eca3970 100644
--- a/local/recipes/dev/llvm-native/recipe.toml
+++ b/local/recipes/dev/llvm-native/recipe.toml
@@ -15,7 +15,47 @@ script = """
 DYNAMIC_INIT
 ARCH="$(echo "${TARGET}" | cut -d - -f1)"
 
-generate_cookbook_cmake_file "$COOKBOOK_HOST_TARGET" "" "$COOKBOOK_TOOLCHAIN" native.cmake
+# Save and unset the cross-compile flags DYNAMIC_INIT exports so the host cc
+# in the native sub-build (CROSS_TOOLCHAIN_FLAGS_NATIVE below) links against
+# the host libc, not the Redox sysroot's relibc — otherwise the native cmake
+# try_compile fails with "undefined reference to __libc_start_main". The cross
+# build restores them via -DCMAKE_*_FLAGS further down. Mirrors the llvm21
+# recipe, which solved this exact failure.
+_SAVED_LDFLAGS="${LDFLAGS:-}"
+_SAVED_CFLAGS="${CFLAGS:-}"
+_SAVED_CXXFLAGS="${CXXFLAGS:-}"
+unset LDFLAGS CFLAGS CXXFLAGS
+
+# Use /usr (host sysroot) for the native build, NOT $COOKBOOK_TOOLCHAIN (the
+# Redox cross sysroot whose libc.a lacks __libc_start_main).
+generate_cookbook_cmake_file "$COOKBOOK_HOST_TARGET" "" "/usr" native.cmake
+
+# The generated native.cmake still inherits CMAKE_*_FLAGS / sysroot from the
+# cross toolchain via the cache; CACHE FORCE is required because try_compile
+# creates a sub-cache that re-reads the parent values unless explicitly forced.
+cat >> native.cmake <<'NATIVE_EOF'
+
+# Override cross-sysroot flags so the host cc links against the host libc.
+set(CMAKE_C_FLAGS "" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS "" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_DEBUG "" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELEASE "" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_DEBUG "" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELEASE "" CACHE STRING "" FORCE)
+set(CMAKE_LDFLAGS "" CACHE STRING "" FORCE)
+set(CMAKE_LDFLAGS_DEBUG "" CACHE STRING "" FORCE)
+set(CMAKE_LDFLAGS_RELEASE "" CACHE STRING "" FORCE)
+set(CMAKE_EXE_LINKER_FLAGS "" CACHE STRING "" FORCE)
+set(CMAKE_SHARED_LINKER_FLAGS "" CACHE STRING "" FORCE)
+set(CMAKE_C_IMPLICIT_LINK_DIRECTORIES "" CACHE STRING "" FORCE)
+set(CMAKE_CXX_IMPLICIT_LINK_DIRECTORIES "" CACHE STRING "" FORCE)
+set(CMAKE_SYSROOT "" CACHE STRING "" FORCE)
+set(CMAKE_FIND_ROOT_PATH "" CACHE STRING "" FORCE)
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM "NEVER" CACHE STRING "" FORCE)
+set(ENV{LDFLAGS} "")
+set(ENV{CFLAGS} "")
+set(ENV{CXXFLAGS} "")
+NATIVE_EOF
 
 case "${ARCH}" in
     x86 | x86_64) LLVM_TARGETS_TO_BUILD="X86";;
@@ -44,7 +84,6 @@ COOKBOOK_CMAKE_FLAGS+=(
     -DCLANG_LINK_CLANG_DYLIB=ON
     -DLIBCLANG_BUILD_STATIC=1
     -DCROSS_TOOLCHAIN_FLAGS_NATIVE="-DCMAKE_TOOLCHAIN_FILE=$(realpath native.cmake)"
-    -DCMAKE_CXX_FLAGS="--std=gnu++11"
     -DBUILD_SHARED_LIBS=False
     -DLLVM_BUILD_EXAMPLES=Off
     -DLLVM_BUILD_TESTS=Off
@@ -64,6 +103,24 @@ COOKBOOK_CMAKE_FLAGS+=(
 )
 
 COOKBOOK_SOURCE="$COOKBOOK_SOURCE/llvm"
+
+# Restore the cross-compile flags for the CROSS build via cmake vars rather
+# than the environment: an exported LDFLAGS leaks into the native try_compile
+# and re-introduces the Redox libc link failure. (Native.cmake above keeps the
+# host sub-build clean.)
+if [ -n "${_SAVED_LDFLAGS}" ]; then
+    COOKBOOK_CMAKE_FLAGS+=(-DCMAKE_EXE_LINKER_FLAGS="${_SAVED_LDFLAGS}")
+    COOKBOOK_CMAKE_FLAGS+=(-DCMAKE_SHARED_LINKER_FLAGS="${_SAVED_LDFLAGS}")
+fi
+if [ -n "${_SAVED_CFLAGS}" ]; then
+    COOKBOOK_CMAKE_FLAGS+=(-DCMAKE_C_FLAGS="${_SAVED_CFLAGS}")
+fi
+if [ -n "${_SAVED_CXXFLAGS}" ]; then
+    COOKBOOK_CMAKE_FLAGS+=(-DCMAKE_CXX_FLAGS="--std=gnu++11 ${_SAVED_CXXFLAGS}")
+else
+    COOKBOOK_CMAKE_FLAGS+=(-DCMAKE_CXX_FLAGS="--std=gnu++11")
+fi
+
 cookbook_cmake
 
 # Create unprefixed symlinks for native use