Outdated yarn lockfile error on deploying app on heroku RRS feed

  • Question

  • User521171331 posted

    I have a working app run locally in node.js and for deployment, I signed up on Heroku and have connected GitHub to Heroku. But when I git push and ran the app, it says:

    Application error. An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details. You can do this from the Heroku CLI with the command

    Then, I went to Heroku from the web browser and under "Manual deploy", I click "Deploy Branch" and get this list of errors:

     -----> Node.js app detected
        -----> Creating runtime environment
        -----> Installing binaries
               engines.node (package.json):  unspecified
               engines.npm (package.json):   unspecified (use default)
               engines.yarn (package.json):  unspecified (use default)
               Resolving node version 10.x...
               Downloading and installing node 10.15.1...
               Using default npm version: 6.4.1
               Resolving yarn version 1.x...
               Downloading and installing yarn (1.14.0)...
               Installed yarn 1.14.0
        -----> Building dependencies
               Installing node modules (yarn.lock)
               yarn install v1.14.0
               [1/4] Resolving packages...
               error Your lockfile needs to be updated, but yarn was run with `--frozen-lockfile`.
               info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
        -----> Build failed
         !     Outdated Yarn lockfile
               Your application contains a Yarn lockfile (yarn.lock) which does not
               match the dependencies in package.json. This can happen if you use npm
               to install or update a dependency instead of Yarn.
               Please run the following command in your application directory and check
               in the new yarn.lock file:
               $ yarn install
               $ git add yarn.lock
               $ git commit -m "Updated Yarn lockfile"
               $ git push heroku master
         !     Push rejected, failed to compile Node.js app.
         !     Push failed

    I don't think i have yarn but the error did mentioned yarn.

    Thursday, February 7, 2019 9:17 AM

All replies

  • User283571144 posted

    Hi ngaisteve1,

    According to your description and error message, it says you have used Yarn to install node modules, it generates a yarn.lock file which contains a list of the exact modules that it installed when you ran the command. If the dependencies in package.json change, but a new yarn.lock file is not generated by the Yarn executable we fail the build to prevent subtle bugs and security issues that could affect your application at runtime.

    I suggest you could firstly check your package.json to make sure you have used the yarn.

    If you used it, I suggest you could run yarn install and check in the updated yarn.lock file.

    $ yarn install
    $ git add yarn.lock
    $ git commit -m "Updated Yarn lockfile"
    $ git push heroku master

    Besides, since this issue is mainly related with the node.js and heroku, I suggest you could post this issue on below forum.


    Best Regards,


    Friday, February 8, 2019 2:14 AM