DIAGNOSTIC: isolate AF_UNIX bind EOPNOTSUPP on Windows (throwaway)

Author: hhugo

.github/workflows/workflow.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - master
+      - afunix-diag
   pull_request:
   schedule:
     # Prime the caches every Monday
@@ -53,6 +54,10 @@ jobs:
 
       - run: opam exec -- make all
 
+      - name: AF_UNIX diagnostic
+        if: always() && matrix.os == 'windows-latest'
+        run: opam exec -- dune exec afunix_diag/afunix_diag.exe
+
       - name: Run the test suite
         timeout-minutes: 5
         run: opam exec -- dune runtest

afunix_diag/afunix_diag.ml

@@ -0,0 +1,31 @@
+(* Isolate the AF_UNIX bind EOPNOTSUPP on Windows: test each step conduit does. *)
+let attempt name f =
+  match f () with
+  | () -> Printf.printf "  %-42s OK\n%!" name
+  | exception Unix.Unix_error (e, fn, _) ->
+      Printf.printf "  %-42s FAIL  %s (in %s)\n%!" name (Unix.error_message e) fn
+  | exception e -> Printf.printf "  %-42s FAIL  %s\n%!" name (Printexc.to_string e)
+
+let fresh p = (try Sys.remove p with _ -> ()); p
+let mk () = Unix.socket Unix.PF_UNIX Unix.SOCK_STREAM 0
+let prot fd f = Fun.protect ~finally:(fun () -> try Unix.close fd with _ -> ()) f
+
+let () =
+  Printf.printf "AF_UNIX diag: win32=%b ocaml=%s\n%!" Sys.win32 Sys.ocaml_version;
+  attempt "socket PF_UNIX SOCK_STREAM" (fun () -> Unix.close (mk ()));
+  attempt "bind rel (no setsockopt)" (fun () ->
+    let fd = mk () in prot fd (fun () ->
+      Unix.bind fd (Unix.ADDR_UNIX (fresh "d_rel.sock"))));
+  attempt "setsockopt SO_REUSEADDR" (fun () ->
+    let fd = mk () in prot fd (fun () -> Unix.setsockopt fd Unix.SO_REUSEADDR true));
+  attempt "bind AFTER SO_REUSEADDR (conduit seq)" (fun () ->
+    let fd = mk () in prot fd (fun () ->
+      Unix.setsockopt fd Unix.SO_REUSEADDR true;
+      Unix.bind fd (Unix.ADDR_UNIX (fresh "d_reuse.sock"))));
+  attempt "bind abs path" (fun () ->
+    let fd = mk () in prot fd (fun () ->
+      Unix.bind fd (Unix.ADDR_UNIX (fresh (Filename.concat (Sys.getcwd ()) "d_abs.sock")))));
+  attempt "bind + listen rel" (fun () ->
+    let fd = mk () in prot fd (fun () ->
+      Unix.bind fd (Unix.ADDR_UNIX (fresh "d_lst.sock"));
+      Unix.listen fd 5))

afunix_diag/dune

@@ -0,0 +1,3 @@
+(executable
+ (name afunix_diag)
+ (libraries unix))

afunix_diag/dune-project

@@ -0,0 +1 @@
+(lang dune 3.18)