Add test reproducing gh10254

test/blackbox-tests/test-cases/pkg/pin-stanza/relative-path-outside-workspace.t

@@ -0,0 +1,71 @@
+Demonstrate that you can't use a relative path referring outside the workspace
+in the pin stanza:
+
+  $ . ../helpers.sh
+
+Make a package containing a library:
+  $ mkdir foo
+  $ cat > foo/dune-workspace <<EOF
+  > (lang dune 3.14)
+  > EOF
+  $ cat > foo/dune-project <<EOF
+  > (lang dune 3.14)
+  > (package
+  >  (name foo))
+  > EOF
+  $ cat > foo/dune <<EOF
+  > (library
+  >  (public_name foo))
+  > EOF
+  $ cat > foo/foo.ml <<EOF
+  > let foo = "foo"
+  > EOF
+
+Make a second package depending on the first via a pin:
+  $ mkdir bar
+  $ cd bar
+  $ mkrepo
+  $ add_mock_repo_if_needed
+  $ cat > dune-project <<EOF
+  > (lang dune 3.14)
+  > (pin
+  >  (url file://$PWD/../foo)
+  >  (package (name foo)))
+  > (package
+  >  (name bar)
+  >  (depends foo))
+  > EOF
+  $ cat > dune <<EOF
+  > (executable
+  >  (public_name bar)
+  >  (libraries foo))
+  > EOF
+  $ cat > bar.ml <<EOF
+  > let () = print_endline Foo.foo
+  > EOF
+
+Lock and build the second package to demonstrate that everything works so far:
+  $ dune pkg lock
+  Solution for dune.lock:
+  - foo.dev
+  $ dune exec ./bar.exe
+  foo
+
+Now change the pin to use a relative path:
+  $ cat > dune-project <<EOF
+  > (lang dune 3.14)
+  > (pin
+  >  (url file://../foo)
+  >  (package (name foo)))
+  > (package
+  >  (name bar)
+  >  (depends foo))
+  > EOF
+
+Solving the project now results in an error, though it's still possible to build the project:
+  $ dune clean
+  $ dune pkg lock
+  Error: path outside the workspace: ../foo from .
+  [1]
+  $ dune exec ./bar.exe
+  foo