title: Certificate error when trying to install MSYS2 packages on Windows server
body: <p>I installed MSYS2-64bits on my Windows Server 2016 to support some Linux librairies, such as OpenSSL, which I need in my Ruby on Rails development. MSYS2 has been partially installed with Ruby 2.7, but did not complete due to certificates error messages.</p>
  <p>I first downloaded and install msys2-x86_64-20210725.exe. It took a very long time and finished after a few messages about Updating the trust database:</p>
  <pre><code>==&gt; Generating pacman master key. This may take some time.
  
  ==&gt; Updating trust database...
  
  ==&gt; Appending keys from msys2.gpg...
  
  ==&gt; Locally signing trusted keys in keyring...
  
    -&gt; Locally signed 6 keys.
  ==&gt; Importing owner trust values...
  
  ==&gt; Disabling revoked keys in keyring...
  
    -&gt; Disabled 1 keys.
  ==&gt; Updating trust database...
  </code></pre>
  <p>It stayed about 10 minutes at this stage, but finally declared a successful installation.</p>
  <p>Then I tried to update the existing software by running <strong>pacman -Syuu</strong>. I restarted MSYS2 as requested, typed the statement, and got lots of errors such as the following, repeatedly:</p>
  <pre><code>$ pacman -Syuu
  :: Synchronizing package databases...
   mingw32.db failed to download
   mingw64.db failed to download
   ucrt64.db failed to download
   clang64.db failed to download
   msys.db failed to download
  error: failed retrieving file 'mingw32.db' from mirror.msys2.org : SSL certificate problem: self signed certificate in certificate chain
  error: failed retrieving file 'mingw64.db' from mirror.msys2.org : SSL certificate problem: self signed certificate in certificate chain
  error: failed retrieving file 'ucrt64.db' from mirror.msys2.org : SSL certificate problem: self signed certificate in certificate chain
  warning: too many errors from mirror.msys2.org, skipping for the remainder of this transaction
  </code></pre>
  <p>I am afraid that the corporate proxy could refuse self-signed certificates. Is there a way to obtain correctly signed certificates and finalise the installation of all the packages?</p>
  <p>Thanks for your help!</p>