D-Programming-Language/dmd — pull request #2548 by 9rnsr (2013-09-11 01:03:06+00:00)
Title: Partial fix for Issue 10666 - Appender does not work with a RefCounted type

http://d.puremagic.com/issues/show_bug.cgi?id=10666

Essentially this is neigher dmd nor phobos regression, but recent `Appender` change in 2.064a should not raise "cannot build closure" error.