diff -r 9397d2d76340 runtime/doc/if_pyth.txt
--- a/runtime/doc/if_pyth.txt	Wed Aug 11 23:37:32 2010 +0200
+++ b/runtime/doc/if_pyth.txt	Fri Aug 13 20:15:20 2010 +0200
@@ -348,17 +348,31 @@
 3. Python 3 support only    (-python, +python3 or +python3/dyn)
 4. Python 2 and 3 support   (+python/dyn, +python3/dyn)
 
-You can see that when Python 2 and Python 3 are both supported they must be
-loaded dynamically.
+Some more details on the special case 4:
 
-On Linux/Unix systems this can only be done without importing global symbols.
-In this case python's "import" might fail, if the library expects the symbols 
-to be provided by vim. To work around this 
-1. either the problematic library, or python in case of standard libraries,
-   must be recompiled to link to the according libpython.so file
-   (--enable-shared in case of python).
-2. Or you recompile vim for only one python version.  In this case all symbols
-   can be imported into vim.
+When Python 2 and Python 3 are both supported they must be loaded dynamically.  
+
+When doing this on Linux/Unix systems and importing global symbols, this leads
+to a crash, if the second python version is used.  So either global symbols
+are loaded but only on python version activated, or no global symbols are
+loaded. The latter makes python's "import" fail on libaries that expect the
+symbols to be provided by vim. 
+
+                                                                *:E999*
+Vim's configuration script makes a guess for all libraries based on one
+standard python library (termios).  If importing this library succeeds for
+both python versions, then both will be made available in vim at the same
+time.  If not, only the version first used in a session will be enabled.
+
+Here Vim,s behavior depends on the system in which it was configured.  In a
+system where both versions of python were configure with --enable-shared, both
+versions of python will be activated at the same time.  There will still be
+problems with other third party libraries, that were not linked to libPython.
+
+To work around such problems there are these options
+1. the problematic library is recompiled to link to the according libpython.so
+2. vim is recompiled for only one python version.
+3. you undefine PY_NO_RTLD_GLOBAL in auto/config.h after configuration
 
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  vim:tw=78:ts=8:ft=help:norl: