Key generation fails with strange error

[mniak]

When trying to run the sample of local key generation provided in the documentation, the script fails with a message like that:

docker run -e KEYS_BASE64_ENCODED=false -v $(pwd):/keys -it --rm quantocommons/remote-signer /bin/sh -c '/opt/remote-signer/standalone gen --id="Maria Silva maria.silva@example.com" --bits=4096 && /opt/remote-signer/standalone export > /keys/pub_$(find /keys -name key_* -type f -exec basename {} \; | head -1)'

2021-02-25T21:11:24Z | E | DONE  | NONE | diskBackend              | Error reading to /keys/key_8519DC7043BAB65F: open /keys/key_8519DC7043BAB65F: no such file or directory | {}

I say that this is a strange error because the file does exist.
I even executed a shell and ran the standalone command manually but it does not work.

./standalone gen --id="Maria Silva maria.silva@example.com" --bits=4096

It doesn't seem related to the volume mounting because even when the --volume option is removed the error still occurrs.

[mniak]

I found that the error is benign and does not interrupt the key generation process.