Unknown Syntax Error: Invalid option name ("--production=false") in Heroku deploy of rails app

Question

I have a rails project (rails 6.1 & ruby 3.1.2) which I have deployed to heroku in the past, but now I'm encountering a problem with Heroku. I get the following error:

Counting objects: 80, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (79/79), done.
Writing objects: 100% (80/80), 146.95 KiB | 4.20 MiB/s, done.
Total 80 (delta 54), reused 0 (delta 0)
remote: Updated 9257 paths from fd1836dc
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Building on the Heroku-22 stack
remote: -----> Using buildpacks:
remote:        1. heroku/nodejs
remote:        2. heroku/ruby
remote: -----> Node.js app detected
remote:        
remote: -----> Creating runtime environment
remote:        
remote:        NPM_CONFIG_LOGLEVEL=error
remote:        USE_YARN_CACHE=true
remote:        NODE_VERBOSE=false
remote:        NODE_ENV=production
remote:        NODE_MODULES_CACHE=true
remote:        
remote: -----> Installing binaries
remote:        engines.node (package.json):  >=14.15.5
remote:        engines.npm (package.json):   >=8.0.0
remote:        engines.yarn (package.json):  >=1.22.19
remote:        
remote:        Resolving node version >=14.15.5...
remote:        Downloading and installing node 21.6.2...
remote:        Bootstrapping npm >=8.0.0 (replacing 10.2.4)...
remote:        npm 10.5.0 installed
remote:        Resolving yarn version >=1.22.19...
remote:        Downloading and installing yarn (4.1.0)
remote:        Installed yarn 4.1.0
remote:        
remote: -----> Installing dependencies
remote:        Installing node modules (yarn.lock)
remote:        Unknown Syntax Error: Invalid option name ("--production=false").
remote:        
remote:        $ yarn install [--json] [--immutable] [--immutable-cache] [--refresh-lockfile] [--check-cache] [--check-resolutions] [--inline-builds] [--mode #0]
remote: 
remote: -----> Build failed
remote:        
remote:        We're sorry this build is failing! You can troubleshoot common issues here:
remote:        https://devcenter.heroku.com/articles/troubleshooting-node-deploys
remote:        
remote:        Some possible problems:
remote:        
remote:        - Dangerous semver range (>) in engines.node
remote:          https://devcenter.heroku.com/articles/nodejs-support#specifying-a-node-js-version
remote:        
remote:        Love,
remote:        Heroku
remote:        
remote:  !     Push rejected, failed to compile Node.js app.
remote: 
remote:  !     Push failed
remote:  !
remote:  ! ## Warning - The same version of this code has already been built: de7880c51bf729ba0df031b35e79bcf67efe93a7
remote:  !
remote:  ! We have detected that you have triggered a build from source code with version de7880c51bf729ba0df031b35e79bcf67efe93a7
remote:  ! at least twice. One common cause of this behavior is attempting to deploy code from a different branch.
remote:  !
remote:  ! If you are developing on a branch and deploying via git you must run:
remote:  !
remote:  !     git push heroku <branchname>:main
remote:  !
remote:  ! This article goes into details on the behavior:
remote:  !   https://devcenter.heroku.com/articles/duplicate-build-version
remote: 
remote: Verifying deploy...
remote: 
remote: !   Push rejected to ibz-garden-houses.
remote: 
To https://git.heroku.com/ibz-garden-houses.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/ibz-garden-houses.git'

What I get from the error that is: Unknown Syntax Error: Invalid option name ("--production=false"). Which I think has something to do with yarn. I've tried to remove the yarn.lock file and generate a new one with yarn install, but that didn't work. I've also removed the YARN: PRODUCTION:FALSE from the Heroku config vars, but that didn't have any effect.

I have no other options at the moment. If someone could help me with this, I'd really appreciate it.

Answer 1

In the end the mistake was in my package.json file.

I had this:

  "engines": {
"node": ">=14.15.5",
"npm": ">=8.0.0",
"yarn": ">=1.22.19"
},

But it should be this:

  "engines": {
"node": "14.15.5",
"npm": "8.0.0",
"yarn": "1.22.19"
},

Now it deploys again to Heroku.