Heroku push rejected because gems fail to install - ruby-on-rails

Question

I need some help with this small app I am trying to push to heroku after doing
git add .
git commit -m "message here"
git push heroku master
I get the following error message:
Enumerating objects: 174, done.
Counting objects: 100% (174/174), done.
Delta compression using up to 12 threads
Compressing objects: 100% (156/156), done.
Writing objects: 100% (174/174), 38.41 KiB | 2.40 MiB/s, done.
Total 174 (delta 62), reused 36 (delta 3)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Building on the Heroku-20 stack
remote: -----> Determining which buildpack to use for this app
remote: -----> Ruby app detected
remote: -----> Installing bundler 2.3.10
remote: -----> Removing BUNDLED WITH version in the Gemfile.lock
remote: -----> Compiling Ruby/Rails
remote: -----> Using Ruby version: ruby-2.6.6
remote: -----> Installing dependencies using bundler 2.3.10
remote: Running: BUNDLE_WITHOUT='development:test' BUNDLE_PATH=vendor/bundle BUNDLE_BIN=vendor/bundle/bin BUNDLE_DEPLOYMENT=1 bundle install -j4
remote: /usr/bin/env: ‘ruby\r’: No such file or directory
remote: Bundler Output: /usr/bin/env: ‘ruby\r’: No such file or directory
remote:
remote: !
remote: ! Failed to install gems via Bundler.
remote: !
remote: ! Push rejected, failed to compile Ruby app.
remote:
remote: ! Push failed
remote: Verifying deploy...
remote:
remote: ! Push rejected to damp-spire-06287.
remote:
To https://git.heroku.com/damp-spire-06287.git
! [remote rejected] master -> master (pre-receive hook declined) error: failed to push some refs to 'https://git.heroku.com/damp-spire-06287.git
I am not sure if it is an issue with the bundler version or something else but I need any help if possible. I have tried doing
bundle install and bundle update
and the bundle completes without a hitch. I have been stuck for a while and tried replacing the bundle version to no avail. Thanks in advance!

Answer 1

This error is caused because you have incorrect line endings (CRLF vs. LF) in your repo, which is generally caused when you are working/deploying across Windows and Unix-like environments. Mac/Unix/Linux environments -- which Heroku uses -- use a single linefeed (usually denoted \n) character to terminate a line while Windows uses a carriage return/linefeed pair (\r\n).
If your local repo is on a Windows machine you'll need to convert the files in your repo before pushing to Heroku. You can configure Git to handle the auto-conversion so that you have Windows terminators when you checkout on Windows but maintain the repo with just linefeeds.
To set up the automatic conversion:
% git config --global core.autocrlf input
Git also provides a way to refresh your repo to ensure all the line endings are correct. This can cause merge headaches since this can affect every line in some/all files, so you preferably want to do this on a fully up-to-date repo (i.e., no un-pushed changes).
% git add --renormalize .
% git commit -m "Normalize all the line endings"
https://docs.github.com/en/get-started/getting-started-with-git/configuring-git-to-handle-line-endings