Retry git fetch/pull to make it more resilient to e.g. network outages

lib/functions.sh

@@ -136,6 +136,28 @@ setHostname() {
 	fi
 }
 
+# from: https://gist.github.com/sj26/88e1c6584397bb7c13bd11108a579746
+# ex. use: retry 5 /bin/false
+function retry {
+  local retries=$1
+  shift
+
+  local count=0
+  until "$@"; do
+    exit=$?
+    wait=$((2 ** $count))
+    count=$(($count + 1))
+    if [ $count -lt $retries ]; then
+      echo "Retry $count/$retries exited with code $exit, retrying in $wait seconds..."
+      sleep $wait
+    else
+      echo "Retry $count/$retries exited with code $exit, giving up."
+      return $exit
+    fi
+  done
+  return 0
+}
+
 ##Setting Network properties
 # currently not needed
 #export HOSTIP=$(MSYS_NO_PATHCONV=1 docker run --rm --add-host=host.docker.internal:host-gateway ubuntu cat /etc/hosts | grep 'host.docker.internal' | awk '{print $1}');