Add Support for Heroku-22

[edmorley]

The Heroku-22 stack was just released:
https://devcenter.heroku.com/changelog-items/2429

In Heroku-22, there is no longer a system install of Ruby:
https://devcenter.heroku.com/articles/heroku-22-stack#system-ruby-is-no-longer-installed

This buildpack uses Ruby here:

heroku-buildpack-r/bin/compile

Line 263 in 77319b3

in_chroot /usr/bin/ruby /app/R/etc/copy_libs.rb "/app/R/site-library/**/*.so" 2>&1 > /dev/null

https://github.com/virtualstaticvoid/heroku-buildpack-r/blob/77319b361aee3473fb2a01ab8ea9ef3f18f4edf4/bin/copy_libs.rb

In order for this buildpack to work on Heroku-22, one of the following will be necessary:

1. Have the buildpack vendor Ruby for use by this script (for an example of a buildpack doing this, see Vendor Ruby if an installation is not found heroku/heroku-buildpack-nginx#103).
2. Convert the Ruby script to be a bash script instead.
3. Have users of this buildpack add the heroku/ruby buildpack prior to this one (they will also need to add a minimal Gemfile to their app source, so the Ruby buildpack passes detection).

[virtualstaticvoid]

Luckily, the copy_libs.rb utility is executed within the chroot during slug compilation, which includes Ruby.

[kalorz]

@virtualstaticvoid I can see that the sources have already been updated with support for Heroku-22. But I'm not sure if it's something I do wrong, or the buildpack has not been deployed to AWS yet (or something... not sure how the process looks like 😬 ), but I get errors when I try to add the buildpack to Heroku-22 stack.

When the buildpack is added as https://github.com/virtualstaticvoid/heroku-buildpack-r.git, the build process fails with error:

-----> Downloading buildpack archives from AWS S3
       Downloading https://heroku-buildpack-r.s3.amazonaws.com/latest/heroku-buildpack-r-22-4.1.2-deploy.tar.gz
curl: (22) The requested URL returned error: 403
 !     Push rejected, failed to compile R app.
 !     Push failed

Then the buildpack is added as vsv/heroku-buildpack-r (which resolves to https://buildpack-registry.s3.amazonaws.com/buildpacks/vsv/heroku-buildpack-r.tgz), the build process fails with error:

 !     ERROR: This buildpack is NOT intended for use with the 'heroku-22' stack
       The supported stacks are 'heroku-18' and 'heroku-20'.
       Use the 'heroku stack:set' CLI command to set the appropriate stack.
       See https://devcenter.heroku.com/articles/stack
       Optionally, for greater control and flexibility consider using the Heroku
       container stack together with the heroku-docker-r implementation.
       See https://github.com/virtualstaticvoid/heroku-docker-r for more information.

[virtualstaticvoid]

Yeah, I haven't been able to publish the static assets yet due to test failures with virtualstaticvoid/heroku-buildpack-r-build2#11. I'll revert the update to the main branch in the meantime to avoid any confusion.

[virtualstaticvoid]

@karolsarnacki FYI, the static assets have now been published for heroku-22 stack.

[kalorz]

@virtualstaticvoid Thank you for letting me know. I'm still getting 403 errors when I try to install the buildpack, though:

Buildpack https://github.com/virtualstaticvoid/heroku-buildpack-r.git:

remote: -----> R app detected
remote: -----> Installing R
remote:        Version 4.1.2 will be installed on heroku-22 stack.
remote: -----> Downloading buildpack archives from AWS S3
remote:        Downloading https://heroku-buildpack-r.s3.amazonaws.com/latest/heroku-buildpack-r-22-4.1.2-deploy.tar.gz
remote: curl: (22) The requested URL returned error: 403
remote:  !     Push rejected, failed to compile R app.
remote: 
remote:  !     Push failed

Buildpack vsv/heroku-buildpack-r:

remote: -----> R app detected
remote: -----> Installing R
remote:        Version 4.1.2 will be installed on heroku-22 stack.
remote: -----> Downloading buildpack archives from AWS S3
remote:        Downloading https://heroku-buildpack-r.s3.amazonaws.com/latest/heroku-buildpack-r-22-4.1.2-deploy.tar.gz
remote: curl: (22) The requested URL returned error: 403
remote:  !     Push rejected, failed to compile R app.
remote: 
remote:  !     Push failed

[virtualstaticvoid]

Ah okay, I didn't include 4.1.2 in the heroku-22 build originally (see virtualstaticvoid/heroku-buildpack-r-build2#11).
I set off another build today which included 4.1.2, so your test should now work.

[virtualstaticvoid]

I've also update the README to add a table listing the combination of R and Heroku stack versions.

[kalorz]

@virtualstaticvoid Thank you, that fixed my builds! :)

I think there's one place that's still not updated: https://elements.heroku.com/buildpacks/virtualstaticvoid/heroku-buildpack-r

Thank you for maintaining this buildpack!

[virtualstaticvoid]

Thanks @karolsarnacki

I've done another release on the Elements page, so should be up-to-date now. I need to figure out a GitHub Action to do this, so I don't forget again.

$ heroku buildpacks:versions vsv/heroku-buildpack-r
Version  Released At               Status
───────  ────────────────────────  ─────────
5        2022-07-04T20:44:15.802Z  published
4        2022-07-03T11:58:27.832Z  published
3        2022-06-30T14:47:59.537Z  published
2        2021-10-07T10:31:36.765Z  published
1        2021-10-07T09:55:22.869Z  published