$ poetry install
Installing dependencies from lock file
...
- Installing pyyaml (5.3.1)
[EnvCommandError]
Command ['/root/.cache/pypoetry/virtualenvs/xxx-qtBNWNw5-py3.7/bin/pip', 'install', '--no-deps', 'pyyaml==5.3.1'] errored with the following return code 1, and output: 
Collecting pyyaml==5.3.1
  Cache entry deserialization failed, entry ignored
  Downloading https://files.pythonhosted.org/packages/64/c2/b80047c7ac2478f9501676c988a5411ed5572f35d1beff9cae07d321512c/PyYAML-5.3.1.tar.gz (269kB)
Building wheels for collected packages: pyyaml
  Running setup.py bdist_wheel for pyyaml: started
  Running setup.py bdist_wheel for pyyaml: finished with status 'error'
  Complete output from command /root/.cache/pypoetry/virtualenvs/xxx-qtBNWNw5-py3.7/bin/python3.7 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-k5apwpdq/pyyaml/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /tmp/tmp3opgs21ypip-wheel- --python-tag cp37:
  usage: -c [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
     or: -c --help [cmd1 cmd2 ...]
     or: -c --help-commands
     or: -c cmd --help
  
  error: invalid command 'bdist_wheel'
  
  ----------------------------------------
  Failed building wheel for pyyaml
  Running setup.py clean for pyyaml
Failed to build pyyaml
Installing collected packages: pyyaml
  Running setup.py install for pyyaml: started
    Running setup.py install for pyyaml: finished with status 'error'
    Complete output from command /root/.cache/pypoetry/virtualenvs/xxx-qtBNWNw5-py3.7/bin/python3.7 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-k5apwpdq/pyyaml/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-v6e72ix9-record/install-record.txt --single-version-externally-managed --compile --install-headers /root/.cache/pypoetry/virtualenvs/xxx-qtBNWNw5-py3.7/include/site/python3.7/pyyaml:
    running install
    running build
    running build_py
    creating build
    creating build/lib.linux-x86_64-3.7
    creating build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/dumper.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/tokens.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/loader.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/nodes.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/reader.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/cyaml.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/resolver.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/parser.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/events.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/composer.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/serializer.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/constructor.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/scanner.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/representer.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/__init__.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/emitter.py -> build/lib.linux-x86_64-3.7/yaml
    copying lib3/yaml/error.py -> build/lib.linux-x86_64-3.7/yaml
    running build_ext
    building '_yaml' extension
    creating build/temp.linux-x86_64-3.7
    creating build/temp.linux-x86_64-3.7/ext
    x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -fPIC -I/root/.cache/pypoetry/virtualenvs/xxx-qtBNWNw5-py3.7/include -I/usr/include/python3.7m -c ext/_yaml.c -o build/temp.linux-x86_64-3.7/ext/_yaml.o
    error: [Errno 2] No such file or directory: 'x86_64-linux-gnu-gcc': 'x86_64-linux-gnu-gcc'