Output from $ vulcan build -v -s ffmpegthumbnailer-2.0.8 -d http://www.ffmpeg.org/releases/ffmpeg-1.2.tar.gz

gistfile1.txt

checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for FFMPEG... no
configure: error: Package requirements (libavutil libavformat libavcodec >= 52.26.0 libswscale) were not met:

No package 'libavutil' found
No package 'libavformat' found
No package 'libavcodec' found
No package 'libswscale' found

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively, you may set the environment variables FFMPEG_CFLAGS
and FFMPEG_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
bin/vulcan-make:69:in `chdir': No such file or directory - /app/vendor/ffmpegthumbnailer-2.0 (Errno::ENOENT)
  from bin/vulcan-make:69:in `block (2 levels) in <main>'
	from bin/vulcan-make:18:in `chdir'
	from bin/vulcan-make:18:in `block in <main>'
	from /usr/local/lib/ruby/1.9.1/tmpdir.rb:83:in `mktmpdir'
	from bin/vulcan-make:17:in `<main>'

did you solve this problem? I'm having the same issue.