*cocotb_with_ghdl* uses external libraries to get the components to verify. They are shipped as git submodules. You have to use the `--recursive` option when clone
the *cocotb_with_ghdl* repository to get them: `git clone --recursive https://git.goodcleanfun.de/tmeissner/cocotb_with_ghdl`
Another useful tool is GTKWave, install it if you want to use the waveform files generated by some of the tests.
### Change into docker container & install requirements