slides/yocto-recipe-basics: clarify explanations

Signed-off-by: Michael Opdenacker <[email protected]>

slides/yocto-recipe-basics/yocto-recipe-basics.tex

@@ -440,24 +440,29 @@ \subsection{Organization of a recipe}
 
 \subsection{Applying patches}
 
-\begin{frame}
-  \frametitle{Patches use cases}
+\begin{frame}[fragile]
+  \frametitle{Patch use cases}
   Patches can be applied to resolve build-system problematics:
   \begin{itemize}
     \item To support old versions of a software: bug and security
       fixes.
     \item To fix cross-compilation issues.
-      \begin{itemize}
-        \item In certain simple cases the \code{-e} option of
-          \code{make} can be used.
-        \item The \code{-e} option gives variables taken from the
-          environment precedence over variables from \code{Makefiles}.
-        \item Helps when an upstream \code{Makefile} uses hardcoded
-          \code{CC} and/or \code{CFLAGS}.
-      \end{itemize}
     \item To apply patches before they make their way into the upstream
       version.
   \end{itemize}
+  However, there are cases when patching a \code{Makefile} is unnecessary:
+  \begin{itemize}
+    \item For example, when an upstream \code{Makefile} uses hardcoded
+          \code{CC} and/or \code{CFLAGS}.
+    \item You can call \code{make} with the \code{-e} option
+	  which gives precedence to variables taken from the
+          environment:
+  \end{itemize}
+  \begin{block}{}
+    \begin{minted}{sh}
+EXTRA_OEMAKE = "-e"
+    \end{minted}
+  \end{block}
 \end{frame}
 
 \begin{frame}[fragile]