diff --git a/packages/yaml-windows/yaml-windows.3.1.0/opam b/packages/yaml-windows/yaml-windows.3.1.0/opam
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+opam-version: "2.0"
+synopsis: "Parse and generate YAML 1.1/1.2 files"
+description: """\
+This is an OCaml library to parse and generate the YAML file
+format.  It is intended to interoperable with the [Ezjsonm](https://github.com/mirage/ezjsonm)
+JSON handling library, if the simple common subset of Yaml
+is used.  Anchors and other advanced Yaml features are not
+implemented in the JSON compatibility layer.
+
+The [Yaml module docs](http://anil-code.recoil.org/ocaml-yaml/yaml/Yaml/index.html) are browseable online."""
+maintainer: "Anil Madhavapeddy <anil@recoil.org>"
+authors: [
+  "Anil Madhavapeddy <anil@recoil.org>"
+  "Rizo Isrof <rizo@odis.io>"
+  "Patrick Ferris"
+  "favonia@gmail.com"
+  "Alan J Hu <alanh@ccs.neu.edu>"
+]
+license: "ISC"
+tags: ["org:mirage" "org:ocamllabs"]
+homepage: "https://github.com/avsm/ocaml-yaml"
+doc: "https://avsm.github.io/ocaml-yaml/"
+bug-reports: "https://github.com/avsm/ocaml-yaml/issues"
+depends: [
+  "ocaml-windows" {>= "4.13.0"}
+  "dune" {>= "2.0"}
+  "dune-configurator"
+  "ctypes-windows" {>= "0.14.0"}
+  "bos-windows"
+]
+depexts: [
+  ["libyaml"] {os-distribution = "mxe"}
+]
+build: [
+  ["dune" "build" "-p" "yaml" "-x" "windows" "-j" jobs]
+]
+dev-repo: "git+https://github.com/avsm/ocaml-yaml.git"
+url {
+  src:
+    "https://github.com/avsm/ocaml-yaml/releases/download/v3.1.0/yaml-3.1.0.tbz"
+  checksum: [
+    "sha256=d0a9e0ae2184a69e6d7202bfe3707d10439d31a71241860234b19f020452ecc7"
+    "sha512=69d0ff09abeac475981deefc5a2a09e8707aebe4c7e606671a5a8ffa7055d3519ee9e4823065d89c8c5eedb355015b8d9410286fac721af53d910d924a0711a3"
+  ]
+}
+x-commit-hash: "cc9d389b706f15df3578ba361e03f261972df9f4"