test: repro #11523 (symlinks in directory targets) (#11524)

Signed-off-by: Etienne Millon <[email protected]>

Author: emillon

test/blackbox-tests/test-cases/directory-targets/cache-symlink.t

@@ -0,0 +1,32 @@
+Symlinks in directory targets should go in the shared cache.
+
+See #11523.
+
+  $ export DUNE_CACHE_ROOT=$PWD/.cache
+  $ export DUNE_CACHE=enabled
+
+  $ cat > dune-project << EOF
+  > (lang dune 3.0)
+  > (using directory-targets 0.1)
+  > EOF
+
+  $ cat > dune << EOF
+  > (rule
+  >  (target (dir d))
+  >  (action
+  >   (progn
+  >    (run mkdir -p d)
+  >    (chdir d
+  >     (progn
+  >      (echo building)
+  >      (run touch target)
+  >      (run ln -s target symlink))))))
+  > EOF
+
+  $ dune build d
+  building
+
+  $ dune clean
+
+  $ dune build d
+  building