Failing build: download dependencies from gradle script

In my project I download and unpack dependencies (tarballs with C-libraries SDL, Lua) using a separate gradle task (I specify the task in preassemble tag). To download I use the Gradle plugin https://github.com/michel-kraemer/gradle-download-task

F-Driod build server can't build my app because it can't download dependencies for some reason. But the build server installed on my computer builds perfectly. Maybe you have restrictions on access to the Internet?