Add a release announcement for 9.0+rc1

Author: mattam82

data/releases/9.0+rc1.md

@@ -0,0 +1,50 @@
+---
+kind: rocq
+version: 9.0+rc1
+date: 2025-01-24
+is_latest: true
+is_lts: false
+intro: |
+  This page describes Rocq version **9.0+rc1**, released on
+  Jan 24, 2025. Go [here](/releases) for a list of all releases.
+
+  This is the first release candidate of Rocq 9.
+highlights: |
+  - A single command line tool: `rocq`
+  - Compatibility Coq binaries and packages
+  - Improvements to template and sort polymorphism
+  - Support for quick fixes in LSP-based interfaces (e.g. for deprecations)
+---
+
+## Changes 
+
+See the full [changelog](https://coq.inria.fr/doc/V9.0+rc1/refman/changes.html#changes-in-9-0-0) in the reference manual.
+
+## Installation Instructions
+
+The base proof assistant can be installed as an opam switch with the following commands:
+```bash
+opam update
+opam switch create 4.14.1
+opam repo add coq-core-dev https://coq.inria.fr/opam/core-dev
+opam install rocq-prover.9.0+rc1
+```
+
+Refer to the [general install instructions](/docs/installing-rocq) for more information.
+
+Source Distribution
+-------------------
+
+- [Source
+  tarball](https://github.com/coq/coq/archive/refs/tags/V9.0+rc1.tar.gz)
+  (`.tar.gz`) for compilation under Unix (including Linux and macOS X)
+  and Microsoft Windows (including Cygwin).
+- Also available in
+  [`.zip`](https://github.com/coq/coq/archive/refs/tags/V9.0+rc1.zip)
+  format.
+- [Opam](https://opam.ocaml.org/) is a source-based distribution of
+  OCaml, Rocq and many companion libraries and tools. Compilation and
+  installation are automated by powerful package managers.
+- The official development repo is hosted on
+  [GitHub](https://github.com/coq/coq).
+

src/global/url.ml

@@ -58,6 +58,7 @@ let minor v =
 let patch v =
   match String.split_on_char '.' v with
   | x :: y :: z :: _ -> x ^ "." ^ y ^ "." ^ z
+  | x :: y :: [] -> x ^ "." ^ y
   | _ -> invalid_arg (v ^ ": invalid  version")
 
 let v2 = "https://v2.ocaml.org"