$ ffmpeg -v debug -listen 1 -i rtmp://localhost:6001/live/test -c copy test.mp4
ffmpeg version 2.8.5 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.1)
  configuration: --prefix=/tmp/ffmpeg-build --extra-cflags=-I/tmp/ffmpeg-build/include --extra-ldflags=-L/tmp/ffmpeg-build/lib --bindir=/tmp/ffmpeg-build/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-librtmp --enable-nonfree
  libavutil      54. 31.100 / 54. 31.100
  libavcodec     56. 60.100 / 56. 60.100
  libavformat    56. 40.101 / 56. 40.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 40.101 /  5. 40.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.101 /  1.  2.101
  libpostproc    53.  3.100 / 53.  3.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument 'debug'.
Reading option '-listen' ... matched as AVOption 'listen' with argument '1'.
Reading option '-i' ... matched as input file with argument 'rtmp://localhost:6001/live/test'.
Reading option '-c' ... matched as option 'c' (codec name) with argument 'copy'.
Reading option 'test.mp4' ... matched as output file.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument debug.
Successfully parsed a group of options.
Parsing a group of options: input file rtmp://localhost:6001/live/test.
Successfully parsed a group of options.
Opening an input file: rtmp://localhost:6001/live/test.
Parsing...
Parsed protocol: 0
Parsed host    : localhost
Parsed app     : live
RTMP_Connect0, failed to connect socket. 111 (Connection refused)
rtmp://localhost:6001/live/test: Unknown error occurred