From dce220e51863ca23772b3ef2ab5c1e24799f3931 Mon Sep 17 00:00:00 2001
From: Sam Ford <1584702+samford@users.noreply.github.com>
Date: Wed, 3 Sep 2025 12:34:06 -0400
Subject: [PATCH] Cask::Audit: fix `key not found: :latest` error

`Cask::Audit.audit_livecheck_version` can raise a `key not found:
:latest` error when a hash from livecheck's `latest_version` method
doesn't have a `:latest` value. This error means that livecheck was
unable to identify the latest upstream version but it can only be
understood if the reader knows how this audit is implemented (and it
may also depend on knowing the structure of livecheck's
`latest_version` hash). Without that knowledge, the error doesn't
make it clear which audit is failing and why.

This addresses the issue by using `nil` as the default value for this
`fetch` call and accounting for a `nil` `latest_version` value. This
allows the audit to surface the usual "Version '1.2.3' differs from
'' retrieved by livecheck" failure, which makes it more clear that
livecheck isn't returning a version.
---
 Library/Homebrew/cask/audit.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/cask/audit.rb b/Library/Homebrew/cask/audit.rb
index 8883e6c8bd..7437fa252d 100644
--- a/Library/Homebrew/cask/audit.rb
+++ b/Library/Homebrew/cask/audit.rb
@@ -755,9 +755,9 @@ module Cask
       latest_version = Homebrew::Livecheck.latest_version(
         cask,
         referenced_formula_or_cask: referenced_cask,
-      )&.fetch(:latest)
+      )&.fetch(:latest, nil)
 
-      return :auto_detected if cask.version.to_s == latest_version.to_s
+      return :auto_detected if latest_version && (cask.version.to_s == latest_version.to_s)
 
       add_error "Version '#{cask.version}' differs from '#{latest_version}' retrieved by livecheck."