Thanks, thought as much.

dub --rdmd
Checking dependencies in '/srv/http/blog'
Building configuration application, build type debug
Running rdmd...
Compiling diet template 'index.dt' (compat)...
Compiling diet template 'index.dt' (compat)...
/home/greg/.dub/packages/vibe-d-0.7.15/source/vibe/core/file.d(60): Warning: explicit element-wise assignment templ[16u..__dollar - 1u] = (suffix)[] is better than templ[16u..__dollar - 1u] = suffix
Error: Build command failed with exit code 1

➜  views  cat index.dt
extends layout

block body
    h1 Greg's blog
    p Hello World!

➜  views  cat layout.dt
!!! 5
        title Blog
        block body

I'm following the first steps from the docs.