fix: make package extraDep intransitive

src/lake/Lake/Build/Package.lean

@@ -79,15 +79,12 @@ def Package.maybeFetchBuildCacheWithWarning (self : Package) := do
 def Package.fetchOptRelease := @maybeFetchBuildCacheWithWarning
 
 /--
-Build the `extraDepTargets` for the package and its transitive dependencies.
-Also fetch pre-built releases for the package's' dependencies.
+Build the `extraDepTargets` for the package.
+Also, if the package is a dependency, maybe fetch its build cache.
 -/
 def Package.recBuildExtraDepTargets (self : Package) : FetchM (BuildJob Unit) :=
   withRegisterJob s!"{self.name}:extraDep" do
   let mut job := BuildJob.nil
-  -- Build dependencies' extra dep targets
-  for dep in self.deps do
-    job := job.mix <| ← dep.extraDep.fetch
   -- Fetch build cache if this package is a dependency
   if self.name ≠ (← getWorkspace).root.name then
     job := job.add <| ← self.maybeFetchBuildCacheWithWarning

src/lake/tests/online/test.sh

@@ -18,6 +18,9 @@ $LAKE -v -f git.toml build @Cli:extraDep |
 
 ./clean.sh
 $LAKE -f barrel.lean update
+# Test that a barrel is not fetched for an unbuilt dependency
+$LAKE -v -f barrel.lean build @test:extraDep |
+  grep --color "Cli:optBarrel" && exit 1 || true
 # Test that barrels are not fetched after the build directory is created.
 mkdir -p .lake/packages/Cli/.lake/build
 ($LAKE -v -f barrel.lean build @Cli:extraDep) |