crosvm.updateScript: update to latest git commit

crosvm upstream have advised that we do this rather than tracking
Chrome OS.

Link: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/5921156/1#message-900e2002e62f3f0d0aeeab996bf14ccf17f9d1c9

pkgs/applications/virtualization/crosvm/default.nix

@@ -14,6 +14,9 @@
   virglrenderer,
   wayland,
   wayland-protocols,
+  writeShellScript,
+  unstableGitUpdater,
+  nix-update,
   pkgsCross,
 }:
 
@@ -69,7 +72,15 @@ rustPlatform.buildRustPackage rec {
   buildFeatures = [ "virgl_renderer" ];
 
   passthru = {
-    updateScript = ./update.py;
+    updateScript = writeShellScript "update-crosvm.sh" ''
+      set -ue
+      ${lib.escapeShellArgs (unstableGitUpdater {
+        url = "https://chromium.googlesource.com/crosvm/crosvm.git";
+        hardcodeZeroVersion = true;
+      })}
+      exec ${lib.getExe nix-update} --version=skip
+    '';
+
     tests = {
       musl = pkgsCross.musl64.crosvm;
     };

pkgs/applications/virtualization/crosvm/update.py

@@ -1,57 +0,0 @@
-#! /usr/bin/env nix-shell
-#! nix-shell -p common-updater-scripts nix-update python3
-#! nix-shell -i python
-
-import csv
-import json
-import re
-import shlex
-import subprocess
-from os.path import abspath, dirname, splitext
-from urllib.request import urlopen
-
-# CrOS version numbers look like this:
-# [<chrome-major-version>.]<tip-build>.<branch-build>.<branch-branch-build>
-#
-# As far as I can tell, branches are where internal Google
-# modifications are added to turn Chromium OS into Chrome OS, and
-# branch branches are used for fixes for specific devices.  So for
-# Chromium OS they will always be 0.  This is a best guess, and is not
-# documented.
-with urlopen('https://chromiumdash.appspot.com/cros/download_serving_builds_csv?deviceCategory=ChromeOS') as resp:
-    reader = csv.reader(map(bytes.decode, resp))
-    header = reader.__next__()
-    cr_stable_index = header.index('cr_stable')
-    cros_stable_index = header.index('cros_stable')
-    chrome_version = []
-    platform_version = []
-
-    for line in reader:
-        if line[cr_stable_index] == "no update":
-            continue
-        this_chrome_version = list(map(int, line[cr_stable_index].split('.')))
-        this_platform_version = list(map(int, line[cros_stable_index].split('.')))
-        chrome_version = max(chrome_version, this_chrome_version)
-        platform_version = max(platform_version, this_platform_version)
-
-chrome_major_version = chrome_version[0]
-chromeos_tip_build = platform_version[0]
-release_branch = f'release-R{chrome_major_version}-{chromeos_tip_build}.B'
-
-# Determine the git revision.
-with urlopen(f'https://chromium.googlesource.com/chromiumos/platform/crosvm/+/refs/heads/{release_branch}?format=JSON') as resp:
-    resp.readline() # Remove )]}' header
-    rev = json.load(resp)['commit']
-
-# Determine the patch version by counting the commits that have been
-# added to the release branch since it forked off the chromeos branch.
-with urlopen(f'https://chromium.googlesource.com/chromiumos/platform/crosvm/+log/refs/heads/chromeos..{rev}?format=JSON') as resp:
-    resp.readline() # Remove )]}' header
-    branch_commits = json.load(resp)['log']
-    version = f'{chrome_major_version}.{len(branch_commits)}'
-
-# Update the version, git revision, and hash in crosvm's default.nix.
-subprocess.run(['update-source-version', 'crosvm', f'--rev={rev}', version])
-
-# Update cargoHash.
-subprocess.run(['nix-update', '--version=skip', 'crosvm'])