fatal: destination path '/my/path' already exists and is not an empty directory.

Summary

I have two jobs. First job displays information about the repository. The second job clones another repository because it's needed as a dependency to compile the code. The first time a pipeline is created, it completes both jobs successfully. The second time a pipeline is created, the second job fails because the directory where the dependency repository is cloned into is already there, from the first pipeline. Thereby generating the error: fatal: destination path '/my/path' already exists and is not an empty directory.

Steps to reproduce

Create a job that clones a repository into the /builds directory. Run it twice, and the second time should fail since the cloned repo is still present.

.gitlab-ci.yml 
    stage: dependencies
    script:
        - git clone https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.com/staging-fw/my_dependencies.git /builds/dependencies

Actual behavior

The second time a pipeline is created, the /builds directory already contains the /builds/dependencies folder.

Expected behavior

Since I'm using docker, my expectation is that the Docker container created for the pipeline will be blank and not contain any previous folders/files that were used in previous containers. That is obviously not the case since the /builds directory used by gitlab-runner contains previous content and is shared among every pipeline that is created.

Relevant logs and/or screenshots

job log 
  on old_gen_runner 6fsjs96e
Using Docker executor with image gcc-arm_4_7-2013q3:3.0 ...
Using docker image sha256:5d4741a428654beb44a3c004822e4d2ceededc88f22ec1ec7f45dedf707a0302 for gcc-arm_4_7-2013q3:3.0 ...
Running on runner-6fsjs96e-project-13664495-concurrent-0 via my_laptop.local...
Fetching changes with git depth set to 50...
Initialized empty Git repository in /builds/staging-fw/my-project/.git/
Created fresh repository.
From https://gitlab.com/staging-fw/my-project
 * [new branch]      master     -> origin/master
Checking out 139f4bdd as master...

Skipping Git submodules setup
$ python /scripts/info.py
Printing job info...

Builds dir: /builds

Commit Message: 
Modified yml file.

Branch: master

Project dir: /builds/staging-fw/my-project
$ ls /builds
my-project

$ git clone https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.com/staging-fw/my_dependencies.git /builds/dependencies
Cloning into '/builds/dependencies'...
Job succeeded

One thing to note is that the first time a pipeline is created it displays:

Initialized empty Git repository

The second time a pipeline is created, the log output is as follows:

Running with gitlab-runner 12.2.0 (a987417a)
  on old_gen_runner 6fsjs96e
Using Docker executor with image gcc-arm_4_7-2013q3:3.0 ...
Using docker image sha256:5d4741a428654beb44a3c004822e4d2ceededc88f22ec1ec7f45dedf707a0302 for gcc-arm_4_7-2013q3:3.0 ...
Running on runner-6fsjs96e-project-13664495-concurrent-0 via my-laptop.local...
Fetching changes with git depth set to 50...
Reinitialized existing Git repository in /builds/staging-fw/my-project/.git/
From https://gitlab.com/staging-fw/my-project
   722c2c3..f321b75  master     -> origin/master
Checking out f321b75f as master...

Skipping Git submodules setup
$ python /scripts/info.py
Printing job info...

Builds dir: /builds

Commit Message: 
Modified yml file.

Branch: master

Project dir: /builds/staging-fw/my-project
$ ls /builds
my-project
tools

This time the log output said:

Reinitialized existing Git repository

And this time it listed two folders in the /builds directory:

$ ls /builds
staging-fw
tools

This indicates to me that the /builds directory is not created individually for each Docker container and is in fact shared between all pipelines. Is this correct? Because I can't find any documentation on this.

Environment description

I am using gitlab-runner and Docker on my MacBook Pro running Mojave v10.14.6.

My repos are hosted on GitLab.com.

gitlab-runner:

Version: 12.2.0 Git revision: a987417a Git branch: 12-2-stable GO version: go1.8.7 Built: 2019-08-22T13:06:00+0000 OS/Arch: darwin/amd64

docker:

Docker version 19.03.1, build 74b1e89

Client: Debug Mode: false

Server: Containers: 5 Running: 0 Paused: 0 Stopped: 5 Images: 36 Server Version: 19.03.1 Storage Driver: overlay2 Backing Filesystem: extfs Supports d_type: true Native Overlay Diff: true Logging Driver: json-file Cgroup Driver: cgroupfs Plugins: Volume: local Network: bridge host ipvlan macvlan null overlay Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog Swarm: inactive Runtimes: runc Default Runtime: runc Init Binary: docker-init containerd version: 894b81a4b802e4eb2a91d1ce216b8817763c29fb runc version: 425e105d5a03fabd737a126ad93d62a9eeede87f init version: fec3683 Security Options: seccomp Profile: default Kernel Version: 4.9.184-linuxkit Operating System: Docker Desktop OSType: linux Architecture: x86_64 CPUs: 4 Total Memory: 1.952GiB Name: docker-desktop ID: DGZ6:2TO4:OFDJ:MTXA:DUWZ:R3ZN:KWGA:F5UJ:Z4RM:2ABB:53O5:F3RL Docker Root Dir: /var/lib/docker Debug Mode: true File Descriptors: 30 Goroutines: 46 System Time: 2019-09-04T00:12:39.5088795Z EventsListeners: 2 HTTP Proxy: gateway.docker.internal:3128 HTTPS Proxy: gateway.docker.internal:3129 Registry: https://index.docker.io/v1/ Labels: Experimental: false Insecure Registries: 127.0.0.0/8 Live Restore Enabled: false Product License: Community Engine

config.toml contents 
 concurrent = 1
 check_interval = 0
 
 [session_server]
   session_timeout = 1800
 
 [[runners]]
   name = "old_gen_runner"
   url = "https://gitlab.com"
   token = "6xxxxxxxxxxxxxxxxx"
   executor = "docker"
   [runners.custom_build_dir]
   [runners.docker]
     tls_verify = false
     image = "gcc:5.2.0"
     privileged = false
     disable_entrypoint_overwrite = false
     oom_kill_disable = false
     disable_cache = false
     volumes = ["/cache"]
     shm_size = 0
     pull_policy = "never"
   [runners.cache]
     [runners.cache.s3]
     [runners.cache.gcs]

Used GitLab Runner version

gitlab-runner: 

Version:      12.2.0
Git revision: a987417a
Git branch:   12-2-stable
GO version:   go1.8.7
Built:        2019-08-22T13:06:00+0000
OS/Arch:      darwin/amd64

Using Docker version 19.03.1, build 74b1e89 executor with custom image gcc-arm_4_7-2013q3:3.0

-->

Possible fixes

I don't have a recommendation for a fix, I'm simply trying to understand why this is happening. If this is expected then it's fine, I just want to understand why and how. Thank you.

Edited by Eddie Garcia