Update config.yml

Author: mcafaro

.circleci/config.yml

@@ -20,6 +20,14 @@ jobs:
           command: |
             sudo sed -i 's|http://archive.ubuntu.com|http://us-east-1.ec2.archive.ubuntu.com|g' /etc/apt/sources.list
             sudo sed -i 's|http://security.ubuntu.com|http://us-east-1.ec2.archive.ubuntu.com|g' /etc/apt/sources.list
+      # Make APT more robust to network connectivity issues.
+      - run:
+          name: Configure APT behavior
+          command: |
+            echo 'Acquire::ForceIPv4 "true";' | sudo tee /etc/apt/apt.conf.d/99force-ipv4
+            echo 'Acquire::http::Timeout "30";' | sudo tee /etc/apt/apt.conf.d/99timeout
+            echo 'Acquire::Retries "3";' | sudo tee /etc/apt/apt.conf.d/99retries
+            echo 'Acquire::http::Pipeline-Depth "0";' | sudo tee /etc/apt/apt.conf.d/99pipeline
       - matlab/install:
           products: Optimization_Toolbox Curve_Fitting_Toolbox
       - matlab/run-tests: