diff --git a/faq.rst b/faq.rst
--- a/faq.rst
+++ b/faq.rst
@@ -308,7 +308,8 @@
 the build process, you may sometimes run into issues when attempting to
 switch between Python 2.x and Python 3.x branches. In these cases, it is
 best to run a ``make distclean`` to ensure that all previously built files
-are removed.
+are removed.  Also see the section on :ref:`Build Troubleshooting
+<build-troubleshooting>`.
 
 
 I want to keep a separate working copy per development branch, is it possible?
@@ -805,6 +806,30 @@
 .. _configuration options: http://www.selenic.com/mercurial/hgrc.5.html
 
 
+.. _build-troubleshooting:
+
+Build Troubleshooting
+=====================
+
+How do I fix "SyntaxError: invalid syntax" in Parser/asdl_c.py?
+---------------------------------------------------------------
+
+If you get an error like the following when building::
+
+   ...
+     File "./Parser/asdl_c.py", line 1
+      print "Must specify exactly one output file"
+                                               ^
+   SyntaxError: invalid syntax
+   make: *** [Include/Python-ast.h] Error 1
+
+it may be because you :ref:`switched from a 3.x branch to a 2.x branch
+<hg-switch-branches>` before building.  Try the following before running the
+build command again::
+
+    $ touch Include/Python-ast.h Python/Python-ast.c
+
+
 SSH
 =======
 
@@ -924,5 +949,5 @@
 message, then it is necessary to identify any Python build directories as
 auto-load safe. One way to achieve this is to add a line like the following
 to ``~/.gdbinit`` (edit the specific list of paths as appropriate)::
-    
+
     add-auto-load-safe-path ~/devel/py3k:~/devel/py32:~/devel/py27
diff --git a/setup.rst b/setup.rst
--- a/setup.rst
+++ b/setup.rst
@@ -76,6 +76,8 @@
 only on pure Python code the pydebug build provides several useful checks that
 one should not skip.
 
+If you encounter unexpected errors when compiling, also consult the
+:ref:`Build Troubleshooting <build-troubleshooting>` section of the FAQ.
 
 Build dependencies
 ''''''''''''''''''