使用 pyenv 安装 python 时出现“无模块 dbm”

Question

I'm looking to use pyenv to manage multiple python versions within a docker image. I'm currently having an issue when running python2.7.17 in a debian:buster-slim image where it is missing a package dbm :

Python 2.7.17 (default, Apr 22 2021, 18:07:32)
[GCC 8.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import dbm
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named dbm

What's interesting the system version of python loads this module just fine:

Python 2.7.16 (default, Oct 10 2019, 22:02:15)
[GCC 8.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import dbm
>>> print(dbm)
<module 'dbm' from '/usr/lib/python2.7/lib-dynload/dbm.x86_64-linux-gnu.so'>

Pyenv Python3 install does not have this issue. This is only occurring with Python2.7.

I found this post which is some what related but had no luck with the solution: GDBM doesn't work with Python 3.6 and anaconda

Any ideas why I'm missing dbm.so when using pyenv but not when using my system version python?

Answer 1

I fixed this by placing the pyenv install commands at the top of the Dockerfile before any other custom build logic:

RUN apt-get update && apt-get install -y --no-install-recommends \
    curl \
    ca-certificates \
    build-essential \
    git \
    unzip \
    bzip2 \
    libsqlite3-dev \
    libssl-dev \
    libbz2-dev \
    libffi-dev \
    libdb-dev \
    python-gdbm \
    libreadline-dev \
    python-openssl \
    zlib1g-dev \
    build-essential \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*
ENV PREV_USER="$USER"
ENV PYENV_ROOT=/home/myuser/.pyenv
ENV PATH="$PYENV_ROOT/shims:$PYENV_ROOT/bin:$PATH"
USER myuser
SHELL ["/bin/bash", "-o", "pipefail", "-c"]
RUN curl https://pyenv.run | bash \
    && eval "$(pyenv init -)" \
    && eval "$(pyenv virtualenv-init -)" \
    && pyenv install 2.7.17 \
    && pyenv install 3.6.10
USER $PREV_USER

Not sure about the specifics but it works now.