2 files changed, 53 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/development/ocaml-modules/opam-repository/default.nix b/nixpkgs/pkgs/development/ocaml-modules/opam-repository/default.nix
new file mode 100644
index 00000000000..1801a9e1c86
--- /dev/null
+++ b/nixpkgs/pkgs/development/ocaml-modules/opam-repository/default.nix
@@ -0,0 +1,24 @@
+{ lib, buildDunePackage, unzip, opam-format, curl }:
+
+buildDunePackage rec {
+  pname = "opam-repository";
+
+  minimumOCamlVersion = "4.02";
+
+  inherit (opam-format) src version;
+
+  patches = [ ./download-tool.patch ];
+  postPatch = ''
+    substituteInPlace src/repository/opamRepositoryConfig.ml \
+      --replace "SUBSTITUTE_NIXOS_CURL_PATH" "\"${curl}/bin/curl\""
+  '';
+
+  nativeBuildInputs = [ unzip ];
+  buildInputs = [ curl ];
+  propagatedBuildInputs = [ opam-format ];
+
+  meta = opam-format.meta // {
+    description = "OPAM repository and remote sources handling, including curl/wget, rsync, git, mercurial, darcs backends";
+    maintainers = with lib.maintainers; [ sternenseemann ];
+  };
+}
diff --git a/nixpkgs/pkgs/development/ocaml-modules/opam-repository/download-tool.patch b/nixpkgs/pkgs/development/ocaml-modules/opam-repository/download-tool.patch
new file mode 100644
index 00000000000..5af720adca9
--- /dev/null
+++ b/nixpkgs/pkgs/development/ocaml-modules/opam-repository/download-tool.patch
@@ -0,0 +1,29 @@
+diff --git a/src/repository/opamRepositoryConfig.ml b/src/repository/opamRepositoryConfig.ml
+index c2954c1d..528fc621 100644
+--- a/src/repository/opamRepositoryConfig.ml
++++ b/src/repository/opamRepositoryConfig.ml
+@@ -27,23 +27,7 @@ type 'a options_fun =
+   'a
+ 
+ let default = {
+-  download_tool = lazy (
+-    try
+-      let tools =
+-        if OpamStd.Sys.(os () = Darwin)
+-        then ["wget", `Default; "curl", `Curl]
+-        else ["curl", `Curl; "wget", `Default]
+-      in
+-      let cmd, kind =
+-        List.find (fun (c,_) -> OpamSystem.resolve_command c <> None) tools
+-      in
+-      [ CIdent cmd, None ], kind
+-    with Not_found ->
+-      OpamConsole.error_and_exit `Configuration_error
+-        "Could not find a suitable download command. Please make sure you \
+-         have either \"curl\" or \"wget\" installed, or specify a custom \
+-         command through variable OPAMFETCH."
+-  );
++  download_tool = lazy ([ CIdent SUBSTITUTE_NIXOS_CURL_PATH, None ], `Curl);
+   validation_hook = None;
+   retries = 3;
+   force_checksums = None;