[Solved] Import Error for Detectron2 after installation on Ubuntu 18.04

[JaninaMattes]

I did install Detectron2 on an Ubuntu 18.04 Bionic Azure insance without GPU access. The Python version is python 3.8. I am using PyTorch 1.8.1 with CPU support. However, when trying to run my python script I receive the following error:

Error Message

File "finetune_net_dla.py", line 29, in <module> from detectron2.evaluation import ( ImportError: cannot import name 'CityscapesEvaluator' from 'detectron2.evaluation' (/anaconda/lib/python3.8/site-packages/detectron2/detectron2/evaluation/__init__.py)

Python Script

My python script's imports look like the following:

import logging import os import datetime from collections import OrderedDict import torch import detectron2.utils.comm as comm from detectron2.checkpoint import DetectionCheckpointer from detectron2.config import get_cfg from detectron2.data import MetadataCatalog from detectron2.engine import DefaultTrainer, default_argument_parser, default_setup, hooks, launch from detectron2.evaluation import ( CityscapesEvaluator, COCOEvaluator, COCOPanopticEvaluator, DatasetEvaluators, LVISEvaluator, PascalVOCDetectionEvaluator, SemSegEvaluator, verify_results, ) from detectron2.modeling import GeneralizedRCNNWithTTA from detectron2.data.datasets import register_coco_instances from detectron2.utils.logger import setup_logger logger = logging.getLogger("detectron2")

What I have done so far

I followed the described INSTALL.md with python -m pip install 'git+https://github.com/facebookresearch/detectron2.git' and also tried git clone https://github.com/facebookresearch/detectron2.git python -m pip install -e detectron2

I further tried it with rm -rf build/ **/*.so. I yet tried to clone the detectron repo into my own repo before I built it and into a different directory; I renamed the folders after the built ... I cloned the Detectron2 repo directly into ../../site-packages . However, I receive the same error even if I try to install everything within a Docker container or simply with a Anaconda environment. If I use which python in Anaconda I receive /anaconda/bin/python and when I use python -m site it returns me

    '/home/mattesjanina1/detectron2_dla',
    '/anaconda/lib/python38.zip',
    '/anaconda/lib/python3.8',
    '/anaconda/lib/python3.8/lib-dynload',
    '/anaconda/lib/python3.8/site-packages',
    '/anaconda/lib/python3.8/site-packages/detectron2',

USER_BASE: '/home/mattesjanina/.local' (exists)
USER_SITE: '/home/mattesjanina/.local/lib/python3.8/site-packages' (doesn't exist)

Under /anaconda/lib/python3.8/site-packages I can find the detectron2 egg.link as follows:

-rw-rw-r--+ 1 mattesjanina1 sudo 47 Jun 30 15:36 detectron2.egg-link -rwxrwxrwx 4 root sudo 152 Jan 25 20:06 distutils-precedence.pth drwxrwsr-x+ 10 root sudo 4096 Jun 1 12:23 docker

My Docker file

My Docker file follows the structure of the ./docker/Dockerfile of the Detectron2 repo and looks like the following:
`FROM python:3.8-slim-buster

RUN apt-get update -y

RUN apt-get -y install apt-utils nano build-essential libglib2.0-0 libsm6 libxext6 libxrender-dev
python3-opencv ca-certificates python3-dev git wget sudo unzip ninja-build &&
rm -rf /var/lib/apt/lists/*

ARG USER_ID=1000
RUN useradd -m --no-log-init --system --uid ${USER_ID} appuser -g sudo
RUN echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
USER appuser
WORKDIR /home/appuser

ENV PATH="/home/appuser/.local/bin:${PATH}"

RUN pip install --user torchtext==0.9.1
RUN pip install --user torchvision torchtext==0.9.1 tensorboard cython cmake pyyaml==5.1 gdown
RUN pip install --user torch==1.8.1+cpu torchvision==0.9.1+cpu torchaudio==0.8.1 -f https://download.pytorch.org/whl/torch_stable.html
RUN pip install --user -U 'git+https://github.com/cocodataset/cocoapi.git#subdirectory=PythonAPI'

RUN mkdir /home/appuser/detectron2_repo
COPY configs/ /home/appuser/detectron2_repo/configs
COPY finetune_net_dla.py /home/appuser/detectron2_repo

WORKDIR /home/appuser/detectron2_repo

RUN pip install --user 'git+https://github.com/facebookresearch/fvcore'

RUN python3 -m pip install --user detectron2 -f https://dl.fbaipublicfiles.com/detectron2/wheels/cpu/index.html

RUN pip install --user pdf2image gunicorn Pillow opencv-python

RUN mkdir /home/appuser/detectron2_repo/datasets

RUN gdown https://drive.google.com/uc?id=XXXX
RUN unzip custom_data.zip -d /home/appuser/detectron2_repo/datasets
RUN rm -r custom_data.zip

RUN mkdir /home/appuser/detectron2_repo/pretrained_models
RUN wget https://www.dropbox.com/sh/wgt9skz67usliei/AADGw0h1y7K5vO0akulyXm-qa/model_final.pth -P /home/appuser/detectron2_repo/pretrained_models/

ENTRYPOINT [ "python3", "finetune_net_dla.py" ]
`
#-----------------------------------------------------------
So far I didn't manage to solve the issue myself. If you have any idea what might cause the problem - I am very glad about any hint or idea 💯 !!.

[JaninaMattes]

The change to from detectron2.evaluation import * solved it for now.