void foo() { align (1) struct bar { int a; } }
I ran into this bug on LDC too (don't have dmd at hand), see this closed bug: http://www.dsource.org/projects/ldc/ticket/399 . It turns out that it's probably a parse error (which implies that it's most likely not implemented in the back end too). Christian Kamm could also reproduce this on dmd. I don't know which version he used though, probably one of the newer 1.05x releases. As a workaround you can of course declare the struct on module level.
Fixed in D2