Recover docs for workspace.default-members

First added in 82d563b71bf697f3d989cc1fdc2455c59679c309 which failed
to update the book and was replaced in
1271bb4de0c0e0a085be239c2418af9c673ffc87.

diff --git a/src/doc/src/reference/manifest.md b/src/doc/src/reference/manifest.md
index 470838e0d97287bc8d3ea1d7dcf8b3b817221cab..95b120e4a2dc58d845410b85d620296c3af75fca 100644 (file)
--- a/src/doc/src/reference/manifest.md
+++ b/src/doc/src/reference/manifest.md
@@ -537,8 +537,19 @@ crate will be treated as a normal package, as well as a workspace. If the
 manifest*.
 
 When working with *virtual manifests*, package-related cargo commands, like
-`cargo build`, default to all packages in the workspace as if `--all` was used.
-This can be changed by passing a `--package` or `-p` command-line parameters.
+`cargo build`, default to the set of packages specified by the `default-members`
+configuration:
+
+```toml
+[workspace]
+members = ["path/to/member1", "path/to/member2", "path/to/member3/*"]
+
+# The members that commands like `cargo build` apply to by deault.
+# This must expand to a subset of `members`.
+# Optional key, defaults to the same as `members`
+# (as if `--all` were used on the command line).
+default-members = ["path/to/member2", "path/to/member3/*"]
+```
 
 #TODO: move this to a more appropriate place
 ### The project layout