I've been using a custom buildpack on Heroku for some time and had been using the BUILDPACK_URL env variable to kick it off during a push.
Recently I bit the bullet and upgraded from Ruby 1.9.3 / Rails 3.2.14 to Ruby 2.2.0 / Rails 4.2.1.rc1 - everything works fine on my development machine, however I am unable to push to Heroku now, and am getting the following error:
~/documents/coding/test$ heroku fork -a vfacelift vupgrade
~/documents/coding/test$ heroku config:unset BUILDPACK_URL -a vupgrade
~/documents/coding/test$ heroku buildpack:set https://github.com/tomwolfe/heroku-buildpack-gsl-ruby.git -a vupgrade
~/documents/coding/test$ git push vupgrade vupgrade:master
Fetching repository, done.
Counting objects: 9723, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (4943/4943), done.
Writing objects: 100% (9723/9723), 82.88 MiB | 758.00 KiB/s, done.
Total 9723 (delta 6948), reused 6422 (delta 4535)
-----> Fetching custom git buildpack... done
-----> Ruby app detected
-----> Compiling Ruby/Rails
!
! Command: 'set -o pipefail; curl --fail --retry 3 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/ruby-2.2.0.tgz -s -o - | tar zxf -' failed unexpectedly:
!
! gzip: stdin: unexpected end of file
! tar: Child returned status 1
! tar: Exiting with failure status due to previous errors
!
! Push rejected, failed to compile Ruby app
To git@heroku.com:vupgrade.git
! [remote rejected] upgrade -> master (pre-receive hook declined)
error: failed to push some refs to 'git@heroku.com:vupgrade.git'
Based on other SO answers, I first unset the BUILDPACK_URL env variable from the forked version and used the heroku buildpack:set CLI command. I also tried setting the STACK env variable to cedar-14 but that didn't seem to make a difference.
Since the buildpack has worked fine for some time and was updated for Rails 4, I doubt the issue lies there.
I also tried using the https://github.com/ddollar/heroku-buildpack-multi.git buildpack and included the .buildpacks file with the following:
https://github.com/tomwolfe/heroku-buildpack-gsl-ruby.git
https://github.com/heroku/heroku-buildpack-ruby.git
And then I tried removing buildpack-ruby from the .buildpacks file as I noticed that Heroku was detecting the app as Ruby anyway through the Gemfile. Both of these failed as before.
Any help is much appreciated...
Thanks, Robert
It appears that the directory structure has changed on AWS where heroku is storing their buildpacks. See https://github.com/heroku/heroku-buildpack-ruby/issues/304 for more info. I forked the https://github.com/tomwolfe/heroku-buildpack-gsl-ruby.git buildpack, added STACK to the ruby URL, allowing buildpack users to set it to cedar or cedar-14 or etc and then created a pull request on the master.