Fix yarn with a HOME dir wrapper

zsh/zshrc

@@ -278,6 +278,8 @@ fi
 export NPM_CONFIG_USERCONFIG="${XDG_CONFIG_HOME}/npm/config"
 export NPM_CONFIG_CACHE="${XDG_CACHE_HOME}/npm"
 export NPM_CONFIG_TMP="${XDG_RUNTIME_DIR}/npm"
+# yarn is not yet able to use XDG-* directories, workaround:
+alias yarn="HOME=${TMPDIR} yarn"
 
 # Sourcing ~/.zshrc