ci: debug network failures while downloading awscli from PyPI

.azure-pipelines/steps/run.yml

@@ -140,9 +140,35 @@ steps:
 # images, etc.
 - bash: |
     set -e
+    # Temporary code to debug #62967.
+    debug_failed_connections() {
+        echo "trying to ping pypi.org"
+        ping pypi.org -c10 || true
+        echo "trying to ping google.com"
+        ping google.com -c10 || true
+        echo "trying to ping 8.8.8.8"
+        ping 8.8.8.8 -c10 || true
+        echo "trying to download pypi.org"
+        curl https://pypi.org || true
+        echo "trying to download from our S3 bucket"
+        curl https://rust-lang-ci2.s3.amazonaws.com || true
+        echo "trying to dig pypi.org"
+        dig pypi.org || true
+        echo "trying to dig files.pythonhosted.org"
+        dig files.pythonhosted.org || true
+        echo "trying to connect to pypi.org with openssl"
+        echo | openssl s_client -connect pypi.org:443 || true
+        echo "trying to connect to files.pythonhosted.org with openssl"
+        echo | openssl s_client -connect files.pythonhosted.org:443 || true
+    }
+    debug_failed_connections_and_fail() {
+        debug_failed_connections
+        return 1
+    }
     source src/ci/shared.sh
     sudo apt-get install -y python3-setuptools
-    retry pip3 install -r src/ci/awscli-requirements.txt --upgrade --user
+    debug_failed_connections
+    retry pip3 install -r src/ci/awscli-requirements.txt --upgrade --user || debug_failed_connections_and_fail
     echo "##vso[task.prependpath]$HOME/.local/bin"
   displayName: Install awscli (Linux)
   condition: and(succeeded(), not(variables.SKIP_JOB), eq(variables['Agent.OS'], 'Linux'))