Node test container not building

[Guilhem-DELAITRE]

This is what I got when launching tests.sh script :

=> [internal] load build definition from Dockerfile.node 
=> => transferring dockerfile: 492B         
=> [internal] load .dockerignore              
=> => transferring context: 2B          
=> [internal] load metadata for docker.io/library/node:10.12.0     
=> [internal] load build context                  
=> => transferring context: 8.33kB            
=> [1/7] FROM docker.io/library/node:10.12.0@sha256:00a7fb3df8e94ed24f42c2920f132f06e92ea5ed69b1c5e53c4bb3d20e85a3e2 
=> CACHED [2/7] RUN apt-get update && apt-get install --upgrade dnsutils python-pip libpython-dev -y          
=> ERROR [3/7] RUN pip install requests PyYAML  
------
> [3/7] RUN pip install requests PyYAML:
#6 0.981 Requirement already satisfied (use --upgrade to upgrade): requests in /usr/lib/python2.7/dist-packages
#6 0.984 Downloading/unpacking PyYAML
#6 1.795   Running setup.py (path:/tmp/pip-build-rIrAWg/PyYAML/setup.py) egg_info for package PyYAML
#6 1.865     Traceback (most recent call last):
#6 1.865       File "<string>", line 17, in <module>
#6 1.865       File "/tmp/pip-build-rIrAWg/PyYAML/setup.py", line 67, in <module>
#6 1.865         import sys, os, os.path, pathlib, platform, shutil, tempfile, warnings
#6 1.865     ImportError: No module named pathlib
#6 1.873     Complete output from command python setup.py egg_info:
#6 1.873     Traceback (most recent call last):
#6 1.873
#6 1.873   File "<string>", line 17, in <module>
#6 1.873
#6 1.873   File "/tmp/pip-build-rIrAWg/PyYAML/setup.py", line 67, in <module>
#6 1.873
#6 1.873     import sys, os, os.path, pathlib, platform, shutil, tempfile, warnings
#6 1.873
#6 1.873 ImportError: No module named pathlib
#6 1.873
#6 1.873 ----------------------------------------
#6 1.873 Cleaning up...
#6 1.885 Command python setup.py egg_info failed with error code 1 in /tmp/pip-build-rIrAWg/PyYAML
#6 1.887 Storing debug log for failure in /root/.pip/pip.log
------
executor failed running [/bin/sh -c pip install requests PyYAML]: exit code: 1