Caching example from docs not working

I get an error running the caching example from the docs.

Gitlab version is 11.0.3, Docker Executor version 11.0.0.

/etc/gitlab-runner/config.toml:

concurrent = 1
check_interval = 0

[[runners]]
  name = "rnd001"
  url = "http://..."
  token = "..."
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "alpine:latest"
    privileged = false
    disable_cache = false
    volumes = ["/cache"]
    shm_size = 0
  [runners.cache]

gitlab-ci.yml:

stages:
- build
- test

job A:
  stage: build
  script:
  - mkdir tmp/
  - echo "build" > tmp/hello.txt
  cache:
    key: build-cache
    paths:
    - tmp/

job B:
  stage: test
  script:
  - cat tmp/hello.txt
  cache:
    key: build-cache

Log JobA

Running with gitlab-runner 11.0.0 (5396d320)
  on rnd001 79ae4976
Using Docker executor with image alpine:latest ...
Pulling docker image alpine:latest ...
Using docker image sha256:11cd0b38bc3ceb958ffb2f9bd70be3fb317ce7d255c8a4c3f4af30e298aa1aab for alpine:latest ...
Running on runner-79ae4976-project-2-concurrent-0 via rnd001...
Fetching changes...
Removing test/
HEAD is now at ca45780 Fix
From http://172.22.31.249/rd/webhmi
   ca45780..165d9c2  feature/ci -> origin/feature/ci
Checking out 165d9c27 as feature/ci...
Skipping Git submodules setup
Checking cache for build-cache-1...
Successfully extracted cache
$ mkdir tmp/
$ echo "build" > tmp/hello.txt
Creating cache build-cache-1...
tmp/: found 2 matching files                       
Created cache
Job succeeded

Log JobB

Running with gitlab-runner 11.0.0 (5396d320)
  on rnd001 79ae4976
Using Docker executor with image alpine:latest ...
Pulling docker image alpine:latest ...
Using docker image sha256:11cd0b38bc3ceb958ffb2f9bd70be3fb317ce7d255c8a4c3f4af30e298aa1aab for alpine:latest ...
Running on runner-79ae4976-project-2-concurrent-0 via rnd001...
Fetching changes...
HEAD is now at 165d9c2 Fix
Checking out 165d9c27 as feature/ci...
Skipping Git submodules setup
$ cat tmp/hello.txt
cat: can't open 'tmp/hello.txt': No such file or directory
ERROR: Job failed: exit code 1

I am probably missing something obvious here. Thanks in advance for the advice.

Anybody?

Hi. Did you found a solution?