Fix README to document mandatory build dependencies

Fix example stratum morphology as well.

1 files changed, 4 insertions, 3 deletions

diff --git a/README b/README
index 82d7d3cb..06409919 100644
--- a/README
+++ b/README
@@ -119,7 +119,7 @@ For strata, use the following fields:
   chunk name), `ref` identifies the commit to use (typically a branch
   name, but any tree-ish git accepts is ok), and `morph` is the name
   of the morphology to use and is optional. In addition to these keys,
-  each of the sources may specify a list of build dependencies using the
+  each of the sources MUST specify a list of build dependencies using the
   `build-depends` field. This field may be omitted to make the source
   depend on all other chunks that are listed earlier in the `sources`
   list. The field may be an empty list to indicate that the chunk does 
@@ -161,13 +161,14 @@ Example stratum:
         "sources": [
             {
                 "name": "fhs-dirs",
-                "ref": "baserock/bootstrap"
+                "ref": "baserock/bootstrap",
+                "build-depends": [],
             },
             {
                 "name": "linux-api-headers",
                 "repo": "linux",
                 "ref": "baserock/morph",
-                "build-depends": []
+                "build-depends": ["fhs-dirs"]
             },
             {
                 "name": "eglibc",