Updating Heroku Buildpack to use ffmpegthumbnailer 2.2.0 - ruby-on-rails

Question

The app I am working on is currently using a buildpack that is using ffmpegthumbnailer 2.0.8 and I need a feature that was added in version 2.1.2. I have forked the repo of the buildpack we are currently using https://github.com/akomic/heroku-buildpack-ffmpegthumbnailer and updated the bin/compile file to point the download_url to "https://github.com/dirkvdb/ffmpegthumbnailer/archive/2.2.0.tar.gz" but when I add my forked repo to the app and run heroku run "ffmpegthumbnailer -version" to verify that it worked I get a bash: ffmpegthumbnailer: command not found error.
Here is the original bin/compile:
#!/bin/sh
indent() {
sed -u 's/^/ /'
}
echo "-----> Install ffmpegthumbnailer"
BUILD_DIR=$1
VENDOR_DIR="vendor"
DOWNLOAD_URL="http://www.aksiom.net/stuff/ffmpegthumbnailer_2.0.8-2.bin.tar.gz"
echo "DOWNLOAD_URL = " $DOWNLOAD_URL | indent
cd $BUILD_DIR
mkdir -p $VENDOR_DIR
cd $VENDOR_DIR
curl -L --silent $DOWNLOAD_URL | tar zx
echo "exporting PATH and LIBRARY_PATH" | indent
PROFILE_PATH="$BUILD_DIR/.profile.d/ffmpeg.sh"
mkdir -p $(dirname $PROFILE_PATH)
echo 'export PATH="$PATH:$HOME/vendor/ffmpegthumbnailer_2.0.8-2/bin"' >> $PROFILE_PATH
echo 'export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$HOME/vendor/ffmpegthumbnailer_2.0.8-2/lib"' >> $PROFILE_PATH
Here is my updated bin/compile in the forked repo:
#!/bin/sh
indent() {
sed -u 's/^/ /'
}
echo "-----> Install ffmpegthumbnailer"
BUILD_DIR=$1
VENDOR_DIR="vendor"
DOWNLOAD_URL="https://github.com/dirkvdb/ffmpegthumbnailer/archive/2.2.0.tar.gz"
echo "DOWNLOAD_URL = " $DOWNLOAD_URL | indent
cd $BUILD_DIR
mkdir -p $VENDOR_DIR
cd $VENDOR_DIR
curl -L --silent $DOWNLOAD_URL | tar zx
echo "exporting PATH and LIBRARY_PATH" | indent
PROFILE_PATH="$BUILD_DIR/.profile.d/ffmpeg.sh"
mkdir -p $(dirname $PROFILE_PATH)
echo 'export PATH="$PATH:$HOME/vendor/ffmpegthumbnailer_2.0.8-2/bin"' >> $PROFILE_PATH
echo 'export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$HOME/vendor/ffmpegthumbnailer_2.0.8-2/lib"' >> $PROFILE_PATH
Other info: I add the buildpack using heroku buildpacks:add <link_to_forked_repo>
Thank you for any help!

Answer 1

This is because the original akomic tarball specified is not the source code, but rather a custom zip of compiled binaries and libraries. Notice that the compile script has no make step, for instance. There is no documentation for how this custom tarball created, but presumably if you go through the same process with a newer version of the source code, and then upload it to a place this script can access it, it will work again. I'm trying to figure this out now.