anchor.diff:    apt-get clean
   
   RUN \
  -  git clone --branch n3.3 --depth 1 https://github.com/FFmpeg/FFmpeg.git && \
  +  git clone --branch $FFMPEG_VERSION --depth 1 https://github.com/FFmpeg/FFmpeg.git && \
     (cd FFmpeg && \
       ./configure \
         --toolchain=hardened \
  
positive.code:   ldconfig
  
  RUN \
    curl -L -o /usr/local/bin/youtube-dl https://yt-dl.org/downloads/2017.05.01/youtube-dl && \
    chmod a+x /usr/local/bin/youtube-dl
  
  RUN \
    curl -L -o /usr/local/bin/tini https://github.com/krallin/tini/releases/download/v0.14.0/tini && \
    chmod a+x /usr/local/bin/tini
  
  COPY . /go/src/github.com/wader/ydls/
  
negative.code: FROM golang:1.8
  MAINTAINER Mattias Wadman mattias.wadman@gmail.com
  
  ENV FFMPEG_VERSION=n3.3
  ENV YDL_VERSION=2017.05.01
  ENV TINI_VERSION=v0.14.0
  
  RUN \
    sed -i 's/main/main contrib non-free/g' /etc/apt/sources.list && \
  