RBENV：使用Docker找不到命令

Question

我正在尝试在Docker环境上使用rbenv安装Ruby 2.7，以下是我Docker文件的相关部分，

FROM ubuntu:20.04
RUN apt-get update && apt-get install -y gnupg2

RUN apt-get update && apt-get dist-upgrade -y && DEBIAN_FRONTEND=noninteractive apt-get install -y git-core zlib1g-dev liblzma-dev patch build-essential libpq-dev libssl-dev libreadline-dev libyaml-dev libxml2-dev libxslt-dev libcurl4-openssl-dev software-properties-common libffi-dev nodejs yarn tzdata imagemagick postgresql postgresql-contrib && rm -rf /var/lib/apt/lists/*

RUN curl -fsSL https://github.com/rbenv/rbenv-installer/raw/HEAD/bin/rbenv-installer | bash
RUN echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
RUN echo 'eval "$(rbenv init -)"' >> ~/.bashrc
SHELL ["/bin/bash", "-c"]
RUN source ~/.bashrc

RUN git clone https://github.com/rbenv/ruby-build.git
RUN PREFIX=/usr/local ./ruby-build/install.sh

RUN rbenv install 2.7.1
RUN gem install bundler

这会导致以下错误有关

#13 1.036 /bin/bash: rbenv: command not found
------
executor failed running [/bin/bash -c rbenv install 2.7.1]: exit code: 127

如何解决此问题的任何帮助，谢谢。