We use Bazel to build TensorFlow.
Official page: link.
The easiest is to download the Bazel binary installer named bazel-<version>-installer-linux-x86_64.deb from the Bazel releases page on GitHub.
Here's an example for v0.21.0
sudo apt install zlib1g-dev # only dependency
wget https://github.com/bazelbuild/bazel/releases/download/0.21.0/bazel_0.21.0-linux-x86_64.deb
sudo dpkg -i bazel_0.21.0-linux-x86_64.deb