fix(setup_board): Install baselayout with USE=build

We need to install baselayout with the build use flag as the very first
package in the new board sysroot to ensure the system's directory
structure is created correctly. This should resolve surprise failures
with the bootengine ebuild.

setup_board

@@ -310,12 +310,6 @@ EOF
 if ! ${HOST_BOARD}; then
   sudo ln -sf "${CHROMIUMOS_CONFIG}/make.conf.${ARCH}-target" \
     "${BOARD_ETC}/make.conf"
-
-  # We install the toolchain related bits after the BOARD_ROOT, BOARD_PROFILE
-  # and BOARD_ETC directories have been created.
-  if [[ ${FLAGS_regen_configs} -eq ${FLAGS_FALSE} ]]; then
-    install_toolchain
-  fi
 fi
 # Setup make.globals and the profile.
 cmds=(
@@ -399,6 +393,14 @@ if ${HOST_BOARD}; then
       sed -i -e "s|$BOARD_ROOT/|/|g"
 else
   if [[ ${FLAGS_regen_configs} -eq ${FLAGS_FALSE} ]]; then
+    # First thing first, install baselayout with USE=build to create a
+    # working directory tree. Don't use binpkgs due to the use flag change.
+    sudo -E USE=build "${EMERGE_WRAPPER}" --usepkg=n --buildpkg=n \
+        --oneshot --quiet --nodeps sys-apps/baselayout
+
+    # Now time for tool chain happy fun time
+    install_toolchain
+
     # Emerge the kernel headers into the board build root.  Use rdeps to
     # avoid pulling any spurious DEPEND things in that we don't care about.
     KERNEL_EMERGE_FLAGS="--select --quiet --root-deps=rdeps"