[FE training-materials-updates] Document two known issues

[Michael Opdenacker]

Repository : git://git.free-electrons.com/training-materials.git

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=181f9b9260903dea82ed57ada5ea0cece40dcdad

>---------------------------------------------------------------

commit 181f9b9260903dea82ed57ada5ea0cece40dcdad
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date:   Wed Jan 30 15:28:23 2013 +0100

    Document two known issues
    
    - Explain how to deal with missing source archives on the Internet
    - Document known issue with gcc-4.7.1 (report and fix by Chris
      Simmonds)


>---------------------------------------------------------------

181f9b9260903dea82ed57ada5ea0cece40dcdad
 labs/sysdev-toolchain/sysdev-toolchain.tex |   31 ++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/labs/sysdev-toolchain/sysdev-toolchain.tex b/labs/sysdev-toolchain/sysdev-toolchain.tex
index 21caf17..c34a80f 100644
--- a/labs/sysdev-toolchain/sysdev-toolchain.tex
+++ b/labs/sysdev-toolchain/sysdev-toolchain.tex
@@ -120,6 +120,37 @@ Nothing is simpler:
 
 And wait!
 
+\subsection{Known issues}
+
+\subsubsection{Source archives not found on the Internet}
+
+It is frequent that Crosstool-ng aborts because it can't find a
+source archive on the Internet, when such an archive has moved or has
+been replaced by more recent versions. New Crosstool-ng versions ship
+with updated URLs, but in the meantime, you need work-arounds.
+
+If this happens to you, what you can do is look for the source archive by
+yourself on the Internet, and copy such an archive to the \code{src}
+directory in your home directory. Note that even source archives
+compressed in a different way (for example, ending with \code{.gz}
+instead of \code{.bz2}) will be fine too. Then, all you have to do is run
+\code{./ct-ng build} again, and it will use the source archive that you
+downloaded.
+
+\subsubsection{ppl-0.10.2 compiling error with gcc 4.7.1}
+
+If you are using gcc 4.7.1, for example in Ubuntu 12.10 (not officially
+supported in these labs), compilation will fail in \code{ppl-0.10.2} with
+the below error:
+
+\begin{verbatim}
+error: 'f_info' was not declared in this scope
+\end{verbatim}
+
+One solution is to add the \code{-fpermissive} flag to the
+\code{CT_EXTRA_FLAGS_FOR_HOST} setting (in \code{Path and misc options
+->  Extra host compiler flags}). 
+
 \section{Testing the toolchain}
 
 You can now test your toolchain by adding