diff --git a/README.md b/README.md
index 2b7959b..b578c0e 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,15 @@ tree diff as the patch. The temporary git repository will be deleted. Before
 dropping into the shell, the script will show you nearby commits, you can try
 to apply `$PATCH_DIR/that_commit.patch` and see if it works for you.
 
+## Publishing
+
+```
+$ echo FULL_COMMIT_ID ...|GIT_DIR=/your/rust/dir/.git ./build-src.sh publish
+```
+
+Again, instead of echoing in the commit IDs, you might pipe in `rustc-commit-db
+list-valid`.
+
 ## Editing patches
 
 To edit all patches, again make a checkout of the rust source. Then, run:
diff --git a/build-src.sh b/build-src.sh
index 4af8ae8..098457c 100755
--- a/build-src.sh
+++ b/build-src.sh
@@ -67,5 +67,5 @@ done
 OLD_GIT_PERM=$(stat --printf=%a .git)
 trap "chmod $OLD_GIT_PERM .git; exit 1" SIGINT
 chmod 000 .git
-cargo package
+cargo ${1:-package}
 chmod $OLD_GIT_PERM .git