test(lib-collision): show dune uses the relevant loc for collision er…

…rors (ocaml#10463)

Signed-off-by: Antonio Nuno Monteiro <anmonteiro@gmail.com>

test/blackbox-tests/test-cases/lib-collision/lib-collision-public-name.t

@@ -0,0 +1,42 @@
+Public libraries using the same library name, in the same context, defined in
+the same folder.
+
+  $ cat > dune-project << EOF
+  > (lang dune 3.13)
+  > (package (name bar) (allow_empty))
+  > (package (name baz) (allow_empty))
+  > EOF
+
+  $ cat > dune << EOF
+  > (library
+  >  (name foo)
+  >  (public_name bar.foo))
+  > (library
+  >  (name foo)
+  >  (public_name baz.foo))
+  > EOF
+
+Without any consumers of the libraries
+
+  $ dune build
+  File "dune", line 5, characters 7-10:
+  5 |  (name foo)
+             ^^^
+  Error: Library "foo" appears for the second time in this directory
+  [1]
+
+  $ rm dune
+  $ mkdir baz bar
+  $ cat > bar/dune << EOF
+  > (library
+  >  (name foo)
+  >  (public_name bar.foo))
+  > EOF
+  $ cat > baz/dune << EOF
+  > (library
+  >  (name foo)
+  >  (public_name baz.foo))
+  > EOF
+
+  $ dune build
+