I tried compiling the CQRLOG in a Docker-image using the existing master branch.

Unfortunately the Dockerfile needs to be updated for the Docker compilation to work due to that the existing Dockerfile uses

FROM ubuntu:eoan

With that version you get a number of missing release files when you try to build the CQRLOG according to the instructions.
FYI also using ubuntu:latest (=focal) will currently not work due to tzdata problems.

-----------
diff --git a/docker-build/Dockerfile b/docker-build/Dockerfile
index feec81e..9ac753a 100644
--- a/docker-build/Dockerfile
+++ b/docker-build/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:eoan
+FROM ubuntu:groovy

RUN apt-get update && apt-get -y upgrade
-----------

With Groovy instead it works fine again.