Superalgos: Docker container crashes on UI startup

I’m trying to testdrive the system using the docker instructions provided in the README but as soon as I reach the Setting up docs search engine message, container crashes with the following message:

[ERROR] Error reading current branch.
Error: Error: spawn git ENOENT
    at Process.ChildProcess._handle.onexit (node:internal/child_process:282:19)
    at onErrorNT (node:internal/child_process:480:16)
    at processTicksAndRejections (node:internal/process/task_queues:83:21)
    at GitExecutorChain.onFatalException (/app/Client/node_modules/simple-git/src/lib/runners/git-executor-chain.js:61:87)
    at GitExecutorChain.<anonymous> (/app/Client/node_modules/simple-git/src/lib/runners/git-executor-chain.js:52:28)
    at Generator.throw (<anonymous>)
    at rejected (/app/Client/node_modules/simple-git/src/lib/runners/git-executor-chain.js:6:65)
[ERROR] Client -> client-> unhandledRejection -> reason = {}
[ERROR] Client -> client-> unhandledRejection -> p = {}

The UI does load pass the docs search engine message, but images are broken because docker container is down. If I restart it, some images work but most not. I’m getting these errors:

[ERROR] httpInterface -> respondWithImage -> onFileRead -> File Not Found: ./Projects/Foundations/Icons/en.png or Error = Error: ENOENT: no such file or directory, open './Projects/Foundations/Icons/en.png'
[ERROR] httpInterface -> respondWithImage -> onFileRead -> File Not Found: ./Projects/Foundations/Icons/bullet/bullet-warning.png or Error = Error: ENOENT: no such file or directory, open './Projects/Foundations/Icons/bullet/bullet-warning.png'

docker 18.09.7 on Ubuntu 18.04, but that shouldn’t matter because this is docker after all.