Remove fdopen's opam

mtelvers · mtelvers · commit 19714b239cb6 · 2026-01-26T21:58:15.000Z
diff --git a/src-opam/opam.ml b/src-opam/opam.ml
@@ -355,6 +355,11 @@ let copy_opams_windows opam_branches =
             aliases)
     empty opam_branches
 
+(* Make native opam-2.2 the default opam.
+   We no longer install fdopen's opam - native opam 2.2+ supports Windows directly. *)
+let setup_default_opam_windows =
+  run {|copy C:\cygwin64\usr\local\bin\opam-2.2.exe C:\cygwin64\bin\opam.exe|}
+
 (* Apk based Dockerfile *)
 let apk_opam2 ?(labels = []) ?arch ~opam_hashes distro () =
   let opam_master_hash, opam_branches = create_opam_branches opam_hashes in
@@ -520,12 +525,13 @@ let windows_mingw_opam2 ?(labels = []) ~override_tag ~opam_hashes (distro : D.t)
   in
   (* 2022-10-12: Docker Engine 20.10.18 on Windows fails copying
      C:\cygwin64, so we cannot build Cygwin in a separate image. *)
-  let ocaml_for_windows =
-    let packages, setup = Windows.Cygwin.install_ocaml_for_windows () in
+  (* We use native opam 2.2+ instead of fdopen's opam, but still need the
+     Cygwin packages that install_ocaml_for_windows would provide. *)
+  let cygwin_setup =
+    let packages, _fdopen_opam_setup = Windows.Cygwin.install_ocaml_for_windows () in
     let packages = Windows.Cygwin.mingw_packages @ packages in
     Windows.Cygwin.install_cygwin ~aslr_off:(aslr_state distro) ~extra:packages
       ()
-    @@ setup
   in
   parser_directive (`Escape '`')
   @@ comment "Autogenerated by OCaml-Dockerfile scripts"
@@ -534,8 +540,9 @@ let windows_mingw_opam2 ?(labels = []) ~override_tag ~opam_hashes (distro : D.t)
   @@ label (("distro_style", "windows") :: labels)
   @@ user "ContainerAdministrator"
   @@ Windows.sanitize_reg_path ()
-  @@ winget_setup @@ ocaml_for_windows
+  @@ winget_setup @@ cygwin_setup
   @@ copy_opams_windows opam_branches
+  @@ setup_default_opam_windows
   @@ Windows.Cygwin.setup () @@ Windows.Cygwin.Git.init ()
 
 (* Native Windows with MSVC and WinGet. *)
@@ -567,18 +574,21 @@ let windows_msvc_opam2 ?(labels = []) ~override_tag ~opam_hashes (distro : D.t)
   in
   (* 2022-10-12: Docker Engine 20.10.18 on Windows fails copying
      C:\cygwin64, so we cannot build Cygwin in a separate image. *)
-  let ocaml_for_windows =
-    let packages, setup = Windows.Cygwin.install_ocaml_for_windows () in
-    Windows.Cygwin.install packages @@ setup
+  (* We use native opam 2.2+ instead of fdopen's opam, but still need the
+     Cygwin packages that install_ocaml_for_windows would provide. *)
+  let cygwin_packages =
+    let packages, _fdopen_opam_setup = Windows.Cygwin.install_ocaml_for_windows () in
+    Windows.Cygwin.install packages
   in
   parser_directive (`Escape '`')
   @@ comment "Autogenerated by OCaml-Dockerfile scripts"
   @@ winget_image @@ cygwin_msvc_image @@ opams_image
   @@ Dockerfile.from "cygwin-msvc"
   @@ label (("distro_style", "windows") :: labels)
   @@ user "ContainerAdministrator"
-  @@ ocaml_for_windows @@ winget_setup
+  @@ cygwin_packages @@ winget_setup
   @@ copy_opams_windows opam_branches
+  @@ setup_default_opam_windows
   @@ Windows.Cygwin.setup () @@ Windows.Cygwin.Git.init ()
 
 let gen_opam2_distro ?override_tag ?(clone_opam_repo = true) ?arch ?labels
