Update README.md

Author: John-Colvin

README.md

@@ -69,3 +69,10 @@ freely be incorporated into Phobos and attribution is not required for binaries.
 consist of code borrowed from other places and are thus required to conform to the terms of these
 licenses.  All are under permissive (i.e. non-copyleft) open source licenses, but some may require 
 binary attribution.  
+
+Known Problems
+--------------
+
+https://issues.dlang.org/show_bug.cgi?id=9449 causes a segfault in ```dstats.tests.friedmanTest``` on the line ```Mean[len] colMeans;```. This is a backend bug and does not affect ldc or gdc.
+
+https://issues.dlang.org/show_bug.cgi?id=13151 (fixed in git HEAD) causes a compile error due to a template ambiguity.