tutorial/thrid-party-software: clarify tree refrence

... emphasizing that it constructs only a single artifact. In
this way, we avoid confusion with globs (that are introduced
later).

1 files changed, 4 insertions, 2 deletions

diff --git a/doc/tutorial/third-party-software.org b/doc/tutorial/third-party-software.org
index 2e1fb77e..5573716c 100644
--- a/doc/tutorial/third-party-software.org
+++ b/doc/tutorial/third-party-software.org
@@ -56,8 +56,10 @@ $ mkdir -p fmt-layer/src
 
 The directory ~include/fmt~ contains only header files. As we want all files in
 this directory to be included in the ~"header directory"~ target, we can safely
-use the explicit ~TREE~ reference[fn:1], which collects /all/ directory contents
-from ~"."~. Note that the ~TARGETS~ file is only part of the overlay, and
+use the explicit ~TREE~ reference[fn:1], which collects, in a single
+artifact (describing a directory) /all/ directory contents
+from ~"."~ of the workspace root. Note that the ~TARGETS~ file is only part of
+the overlay, and
 therefore will not be part of this tree. Furthermore, this tree should be staged
 to ~"fmt"~, so that any consumer can include those headers via ~<fmt/...>~. The
 resulting header directory target ~"hdrs"~ in ~include/fmt/TARGETS~ should be