diff --git a/doc/installation/clang.rst b/doc/installation/clang.rst
index 88cc5e6e..05334e26 100644
--- a/doc/installation/clang.rst
+++ b/doc/installation/clang.rst
@@ -45,3 +45,23 @@ In order to use clang when building TRIQS::
    On OS X, the options -std=c++11 and -stdlib=libc++ are automatically added by the TRIQS
    installation script.
 
+libclang
+----------
+
+Some tools for developers (e.g. automatically C++/Python wrapper generation), use libclang
+(delivered with clang), and its python bindings (usually not given).
+
+The latest version is necessary.
+
+A pip package, updated to the latest version, is on github.
+Install it simply with ::
+
+  pip install -e git+https://github.com/parcollet/python-clang.git#egg=clang
+
+To uninstall it (or another version) ::
+
+  pip uninstall clang
+
+
+  
+
diff --git a/doc/installation/requirements.rst b/doc/installation/requirements.rst
index 8966920d..eb81d6cd 100644
--- a/doc/installation/requirements.rst
+++ b/doc/installation/requirements.rst
@@ -19,16 +19,13 @@ A recent compiler is therefore mandatory.
 
 * Standard compliant C++ compilers (recommended and supported).
   
-  * :ref:`clang 3.2<install_clang>` and higher (in particular the default clang on OS X 10.8).
+  * :ref:`clang 3.3<install_clang>` and higher (in particular the default clang on OS X >= 10.8).
   * g++ 4.8.1 and higher
 
-  * The intel icc 14.0 is close to be C++11 compliant, but presents currently too many bugs to be supported 
+  * The intel icc 15.0 is close to be C++11 compliant, but presents currently too many bugs to be supported 
     at present. It compiles 99% of TRIQS, but we do not have the ressources to write and 
     maintains all necessary workarounds.
     
-    Besides, for *our codes*, icc does not provide a significant speed gain (unlike MKL), 
-    so we do not recommend it for TRIQS.
-
 * C++98 compilers
 
   * g++ before 4.8.1
@@ -67,12 +64,16 @@ Libraries
 +------------------------+----------+------------------------------------------------------------------------+
 | cmake                  | >= 2.8.7 | CMake is used to control the software compilation process              |
 +------------------------+----------+------------------------------------------------------------------------+
+| mako                   | >= 0.9.1 | mako templates are used to generate the C++/python wrapper             |
++------------------------+----------+------------------------------------------------------------------------+
 | pyparsing              | >= ?     | Tool for sphinx (to compile documentation)                             |
 +------------------------+----------+------------------------------------------------------------------------+
 | sphinxcontrib-doxylink | >= ?     | Tool for sphinx (to compile documentation)                             |
 +------------------------+----------+------------------------------------------------------------------------+
 | matplotlib             | >= 0.99  | Python 2D plotting library                                             |
 +------------------------+----------+------------------------------------------------------------------------+
+| libclang               | 3.4      | python bindings of the clang lib (for TRIQS developers ONLY)           |
++------------------------+----------+------------------------------------------------------------------------+
 
 (1)  Since standard linux distributions (and macports on OS X) now provides openmpi, even on laptops, we avoid the unnecessary complication of maintaining a non-parallel version of TRIQS
  
diff --git a/doc/reference/utilities/exceptions.rst b/doc/reference/utilities/exceptions.rst
index 70cfaedd..b9d982ac 100644
--- a/doc/reference/utilities/exceptions.rst
+++ b/doc/reference/utilities/exceptions.rst
@@ -10,13 +10,17 @@ Exceptions
 TRIQS defines special exceptions, with the following characteristics :
 
 * they derives from std::exceptions 
-* their .what() contains: 
+* their method .what() returns : 
 
+  * the date and time of the exception (useful in long QMC computations...).
   * the file and line where the exception occurred
-  * an additionnal error message (see example below). The error behaves like a std::stringstream, 
-    one can accumulate any message
+  * an additionnal error message (see example below). The error behaves like a std::stringstream, one can accumulate any message
+
+* their method .what() returns : 
   * a complete stack strace of the C++ code at the exception point, with demangling of the function name (on gcc and clang).
 
+In addition, we provide a TRIQS_RUNTIME_ERROR macro to throw exception easily, Cf example below.
+
 .. warning::
   
    For uniformity, it is highly recommended to use these macros when developing for TRIQS.
diff --git a/doc/reference/utilities/exceptions_1.cpp b/doc/reference/utilities/exceptions_1.cpp
index 2dfb6e27..4cefd52e 100644
--- a/doc/reference/utilities/exceptions_1.cpp
+++ b/doc/reference/utilities/exceptions_1.cpp
@@ -7,7 +7,8 @@ void f() {
   if (2 != 3) TRIQS_RUNTIME_ERROR << " The condition is false because " << 2 << "!=" << 3;
  }
  catch (triqs::runtime_error const& e) {
-  std::cout << "caught error " << e.what() << std::endl;
+  std::cout << "caught error \n" << e.what() << std::endl;
+  std::cout << "C++ trace = \n" << e.trace() << std::endl;
  }
 }