Cannot push to Heroku (gemfile.lock issue) - ruby-on-rails

Question

Summary:
When pushing to my staging app, Heroku complains that bundle install failed and that I need to run bundle install elsewhere and version the resulting Gemfile.lock. The problem is that I've already done this and committed it.
How do I fix this?
Issue:
Due to some inherited awfulness at work, I had to debug and fix several things in production. Everything's working now, but this means our master branch is ahead of staging by 10+ commits, including some gem changes. I merged them and attempted to push to my staging app on Heroku.
However, I didn't run bundle install after merging in the changes (shame on me), so Heroku correctly complained.
To fix this, I ran the standard:
bundle install
git add Gemfile.lock
git commit -m "Updated gem bundle"
git push staging
However, Heroku is still complaining about Gemfile.lock:
Counting objects: 228, done.
Delta compression using up to 6 threads.
Compressing objects: 100% (179/179), done.
Writing objects: 100% (192/192), 24.38 KiB | 0 bytes/s, done.
Total 192 (delta 127), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Using set buildpack heroku/ruby
remote: -----> Ruby app detected
remote: -----> Compiling Ruby/Rails
remote: -----> Using Ruby version: ruby-2.2.2
remote: -----> Installing dependencies using bundler 1.11.2
remote: Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4 --deployment
remote: You are trying to install in deployment mode after changing
remote: your Gemfile. Run `bundle install` elsewhere and add the
remote: updated Gemfile.lock to version control.
remote: You have deleted from the Gemfile:
remote: * ruby-drupal-hash
remote: Bundler Output: You are trying to install in deployment mode after changing
remote: your Gemfile. Run `bundle install` elsewhere and add the
remote: updated Gemfile.lock to version control.
remote:
remote: You have deleted from the Gemfile:
remote: * ruby-drupal-hash
remote: !
remote: ! Failed to install gems via Bundler.
remote: !
remote:
remote: ! Push rejected, failed to compile Ruby app
remote:
remote: Verifying deploy...
remote:
remote: ! Push rejected to redacted-staging.
remote:
To https://git.heroku.com/redacted-staging.git
! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/redacted-staging.git'
Also:
Gemfile.lock is not in .gitignore
bundle install runs fine, and does not update any gems (as I've run it several times now).
To verify my sanity, I checked git status and git log to ensure I actually added and committed the changes; I'm apparently not crazy (though please correct me if i'm wrong).
To reiterate:
I have already run bundle install and added & committed Gemfile.lock
How do I fix this?
What am I missing?
Update:
I've tried
running bundle update which updated 26 gems; committing the new Gemfile.lock and pushing results in the same error.
Deleting and re-bundling produces an identical Gemfile.lock. Adding a newline and pushing results in the same error.
Removing Bundler's version info from Gemfile.lock and pushing results in the same error.
I even re-addded the ruby-drupal-hash gem, ran bundle install, and pushed the new Gemfile and Gemfile.lock files. Interestingly, the error message about me deleting ruby-drupal-hash persisted despite it being present again.

Answer 1

I assume that you are working locally on different OS then your server is, for example windows vs Unix.
In order to fix it you simply have to build it with the following flag:
bundle install --deployment
If this is not working as well, simply delete the .lock file and let it be generated again in the same flow as you did before with install/update

Answer 2

Yeah, trying to run bundle update or if it didn't work, I think this line it's look interesting:
remote: You have deleted from the Gemfile:
remote: * ruby-drupal-hash
remote: Bundler Output: You are trying to install in deployment mode after changing
remote: your Gemfile. Run `bundle install` elsewhere and add the
remote: updated Gemfile.lock to version control.
remote:
remote: You have deleted from the Gemfile:
remote: * ruby-drupal-hash

Answer 3

It seems it is complaining about ruby-drupal-hash being removed from Gemfile but Gemfile.lock not reflecting it.
You have deleted from the Gemfile:
remote: * ruby-drupal-hash
I would check the Gemfile and Gemfile.lock for that particular gem and see if that is the problem.

Answer 4

The answer was deceptively simple (of course):
git push staging staging:master
The issue was that I was on the staging branch and needed to update my Heroku staging server's master branch.
Shame on me for overlooking something so obvious!
... and shame on Heroku's decidedly unhelpful output.

Answer 5

For future internet explorers, I had a similar situation.
I had to change the version of a gem dependency, so I had to manually add "Execjs, '2.7.0'" to my gemfile, since another gem update had pulled it to 2.8.0 and that was causing an issue on Heroku.
Once I got the dependency updated, I removed the gem from the gemfile (while it remained in the gemfile.lock) and never did a bundle install to clean up the gemfile.lock When I tried to push to Heroku, it broke and I got the same error.
To fix, I ran bundle install on the master branch and then committed the new gemfile.lock and then pushed to Heroku and it deployed as expected.
VERY stressful morning for me! :-)