Read-only file system when running snapcraft from snap

* I'm trying to build a snap.

* I have snapcraft installed from "snap install snapcraft --classic"

When running

$ sudo snapcraft

The build fails with:

...
...
...
File "/root/build_django-gunicorn/parts/django-gunicorn/install/usr/lib/python3.5/os.py", line 241, in makedirs
    mkdir(name, mode)
OSError: [Errno 30] Read-only file system: '/snap/snapcraft/794/django-gunicorn'
Traceback (most recent call last):
  File "/snap/snapcraft/794/bin/snapcraft", line 11, in <module>
    load_entry_point('snapcraft==2.35', 'console_scripts', 'snapcraft')()
...
...
...

* I then remove the snap and replace it with the version from the os:
snapcraft, version 2.35

* Then, the build completed successfully:

Snapping 'django-gunicorn' |
Snapped django-gunicorn_0.1_amd64.snap

$ snap search snapcraft
Name Version Developer Notes Summary
snapcraft 2.35 canonical classic easily create snaps

More information:

* In my snapcraft.yaml, I have this:

...
...
...
parts:
  django-gunicorn:
    plugin: python
    source: .
    python-version: python3
    requirements: requirements.txt
    stage-packages: [libpq-dev,libssl-dev]
    prime:
      - -.venv
    install: |
      mkdir -p $SNAPCRAFT_PART_INSTALL/django-gunicorn
      python3 ./manage.py collectstatic --no-input
      cp -r ./* $SNAPCRAFT_PART_INSTALL/django-gunicorn/
...
...
...

Would this cause problems?