From deb1607d5e75495f3161fe911267620204c0fbd8 Mon Sep 17 00:00:00 2001
From: Sutou Kouhei <kou@clear-code.com>
Date: Wed, 5 Jun 2024 17:13:37 +0900
Subject: [PATCH] GH-41964: [CI][C++] Clear cache for mamba on AppVeyor

It seems that mamba may use invalid download URL when there are
invalid caches.
---
 ci/appveyor-cpp-setup.bat | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ci/appveyor-cpp-setup.bat b/ci/appveyor-cpp-setup.bat
index 5c4a11832d5ee..5a9dffa166fb7 100644
--- a/ci/appveyor-cpp-setup.bat
+++ b/ci/appveyor-cpp-setup.bat
@@ -66,6 +66,9 @@ set CONDA_PACKAGES=%CONDA_PACKAGES% --file=ci\conda_env_cpp.txt
 @rem Force conda to use conda-forge
 conda config --add channels conda-forge
 conda config --remove channels defaults
+@rem Ensure using the latest information. If there are invalid caches,
+@rem mamba may use invalid download URL.
+mamba clean --all -y
 @rem Arrow conda environment
 mamba create -n arrow -y -c conda-forge ^
   --file=ci\conda_env_python.txt ^