Use conda to install tar.bz2 for low bandwidth Internet

For sites with poor Internet connection, conda install mypkg will fail and not resume a partially downloaded package. These download resets can make installing larger Python packages like opencv nearly impossible.

The errors include

CondaError: CondaHTTPError: HTTP 000 CONNECTION FAILED for url


Use that URL from the error message with wget -c to download the package and install directly. This example uses OpenCV 3.3 for Windows from conda-forge.

  1. From Cygwin or WSL:

    wget -c
  2. resume downloading:

    • download interrupted: reissue that command to resume download.
    • download stalls: press Ctrl C and then reissue that command to resume download.
  3. Install from the tar.bz2 file by

    conda install opencv-3.3.0-py36_200.tar.bz2


If the above method still does not work, I have found the pip install OpenCV wheel method to be robust for Windows with a 40 MB .whl download.