How to fix build failures with `create-react-app` in production

[ehmicky]

If your build is using create-react-app and has been failing since approximately the 18th of June 2020, this post will help you fix it.

Why your build might be failing

The build script bootstrapped by create-react-app performs some validation of your code. When most of this validation fails, create-react-app prints a warning message. When this happens inside a CI provider, such as Netlify, create-react-app becomes stricter and makes the build fail as well.

Until recently, Netlify was not setting the CI environment variable, which is the de-facto standard for CI providers to let users and libraries know that a build is run inside a CI environment. This not only created a situation of “works differently in Netlify’s build environment than other CI providers”, but also created problems for folks building tools to integrate with our environment around functionality - things like “make sure my tool doesn’t wait for user input and output progress bars that won’t look good in CI”. However, setting this environment variable had the side effect of triggering the “strict mode” of create-react-app mentioned above, which might have made your build start failing, in case you had existing warnings.

How to detect the problem

If your build is impacted by this problem, the following error message should be visible in your build logs.

Treating warnings as errors because process.env.CI = true.
Most CI servers set it automatically.

If you don’t see that message, your build is failing for a different reason, and the following fix won’t apply.

How to fix your build

First solution (recommended)

Look into your build logs, and find any warnings printed by your build command. Fixing those warnings will make your build succeed again and is a best practice.

Second solution

Find your build command, which should be set either in the Netlify app or in your netlify.toml.

Prefix your build command with CI=. No space should be between CI and =.

Example build command before the fix:

npm run build

Example build command after the fix:

CI= npm run build

---

Hopefully one of these solutions will work for you, but if not, please respond to this post with a link to your build logs and as many details as you think are relevant (for instance: “I saw the error in this deploy: (link to deploy logs) , and I tried to fix by adding a netlify.toml which I quote below. I added that file in directory X in my repository.”), and our team will take a closer look for you.

[kennymanman]

i tried the solutions you posted, but i am still seeing the error

9:49:00 AM: Build ready to start

9:50:18 AM: build-image version: ca811f47d4c1cbd1812d1eb6ecb0c977e86d1a1d

9:50:18 AM: build-image tag: v3.3.20

9:50:18 AM: buildbot version: be8ecf2af866e16fa4301cc5c14de2ccbbb21cf4

9:50:19 AM: Fetching cached dependencies

9:50:19 AM: Starting to download cache of 254.8KB

9:50:19 AM: Finished downloading cache in 59.300018ms

9:50:19 AM: Starting to extract cache

9:50:19 AM: Failed to fetch cache, continuing with build

9:50:19 AM: Starting to prepare the repo for build

9:50:19 AM: No cached dependencies found. Cloning fresh repo

9:50:19 AM: git clone GitHub - kennymanman/LittleRock

9:50:23 AM: Preparing Git Reference refs/heads/master

9:50:25 AM: Different publish path detected, going to use the one specified in the Netlify configuration file: ‘build’ versus ‘build/’ in the Netlify UI

9:50:25 AM: Starting build script

9:50:25 AM: Installing dependencies

9:50:25 AM: Python version set to 2.7

9:50:27 AM: v12.18.0 is already installed.

9:50:27 AM: Now using node v12.18.0 (npm v6.14.4)

9:50:27 AM: Started restoring cached build plugins

9:50:27 AM: Finished restoring cached build plugins

9:50:27 AM: Attempting ruby version 2.7.1, read from environment

9:50:29 AM: Using ruby version 2.7.1

9:50:29 AM: Using PHP version 5.6

9:50:29 AM: 5.2 is already installed.

9:50:29 AM: Using Swift version 5.2

9:50:29 AM: Started restoring cached node modules

9:50:29 AM: Finished restoring cached node modules

9:50:29 AM: Installing NPM modules using NPM version 6.14.4

9:51:04 AM: > core-js@2.6.11 postinstall /opt/build/repo/node_modules/babel-runtime/node_modules/core-js

9:51:04 AM: > node -e “try{require(‘./postinstall’)}catch(e){}”

9:51:04 AM: > core-js@3.6.5 postinstall /opt/build/repo/node_modules/core-js

9:51:04 AM: > node -e “try{require(‘./postinstall’)}catch(e){}”

9:51:05 AM: > core-js-pure@3.6.5 postinstall /opt/build/repo/node_modules/core-js-pure

9:51:05 AM: > node -e “try{require(‘./postinstall’)}catch(e){}”

9:51:07 AM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/webpack-dev-server/node_modules/fsevents):

9:51:07 AM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

9:51:07 AM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/watchpack-chokidar2/node_modules/fsevents):

9:51:07 AM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

9:51:07 AM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/jest-haste-map/node_modules/fsevents):

9:51:07 AM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

9:51:07 AM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.1.2 (node_modules/fsevents):

9:51:07 AM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.1.2: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

9:51:07 AM: added 1712 packages from 833 contributors and audited 1720 packages in 36.704s

9:51:08 AM: 67 packages are looking for funding

9:51:08 AM: run npm fund for details

9:51:08 AM: found 4997 low severity vulnerabilities

9:51:08 AM: run npm audit fix to fix them, or npm audit for details

9:51:13 AM: NPM modules installed

9:51:14 AM: Started restoring cached go cache

9:51:14 AM: Finished restoring cached go cache

9:51:14 AM: go version go1.14.4 linux/amd64

9:51:15 AM: go version go1.14.4 linux/amd64

9:51:15 AM: Installing missing commands

9:51:15 AM: Verify run directory

9:51:17 AM: ​

9:51:17 AM: ┌─────────────────────────────┐

9:51:17 AM: │ Netlify Build │

9:51:17 AM: └─────────────────────────────┘

9:51:17 AM: ​

9:51:17 AM: ❯ Version

9:51:17 AM: @netlify/build 3.0.1

9:51:17 AM: ​

9:51:17 AM: ❯ Flags

9:51:17 AM: deployId: 5f25e34bff928d349fcb94b0

9:51:17 AM: mode: buildbot

9:51:17 AM: ​

9:51:17 AM: ❯ Current directory

9:51:17 AM: /opt/build/repo

9:51:17 AM: ​

9:51:17 AM: ❯ Config file

9:51:17 AM: No config file was defined: using default values.

9:51:17 AM: ​

9:51:17 AM: ❯ Context

9:51:17 AM: production

9:51:17 AM: ​

9:51:17 AM: ┌───────────────────────────────────┐

9:51:17 AM: │ 1. Build command from Netlify app │

9:51:17 AM: └───────────────────────────────────┘

9:51:17 AM: ​

9:51:17 AM: $ CI= npm run build

9:51:26 AM: > little-rock@0.1.0 build /opt/build/repo

9:51:26 AM: > react-scripts build

9:51:27 AM: Creating an optimized production build…

9:51:30 AM: Failed to compile.

9:51:30 AM:

9:51:30 AM: ./src/App.js

9:51:30 AM: Cannot find module: ‘react-router-dom’. Make sure this package is installed.

9:51:30 AM: You can install this package by running: npm install react-router-dom.

9:51:30 AM: npm ERR! code ELIFECYCLE

9:51:30 AM: npm ERR! errno 1

9:51:30 AM: npm ERR! little-rock@0.1.0 build: react-scripts build

9:51:30 AM: npm ERR! Exit status 1

9:51:30 AM: npm ERR!

9:51:30 AM: npm ERR! Failed at the little-rock@0.1.0 build script.

9:51:30 AM: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

9:51:35 AM: npm ERR! A complete log of this run can be found in:

9:51:35 AM: npm ERR! /opt/buildhome/.npm/_logs/2020-08-01T21_51_30_960Z-debug.log

9:51:35 AM:

9:51:35 AM: If the build failed with a warning about “process.env.CI = true”, this is due to “create-react-app” treating warnings as errors when in CI. In order to fix this problem, please either:

9:51:35 AM: - Fix the issues highlighted by the warnings above.

9:51:35 AM: - Or modify the “scripts.build” command in your “package.json” from “react-scripts build” to “CI= react-scripts build”

9:51:35 AM: More information can be found at Build troubleshooting tips | Netlify Docs

9:51:35 AM: ​

9:51:35 AM: ┌─────────────────────────────┐

9:51:35 AM: │ “build.command” failed │

9:51:35 AM: └─────────────────────────────┘

9:51:35 AM: ​

9:51:35 AM: Error message

9:51:35 AM: Command failed with exit code 1: CI= npm run build

9:51:35 AM: ​

9:51:35 AM: Error location

9:51:35 AM: In Build command from Netlify app:

9:51:35 AM: CI= npm run build

9:51:35 AM: ​

9:51:35 AM: Resolved config

9:51:35 AM: build:

9:51:35 AM: command: CI= npm run build

9:51:35 AM: commandOrigin: ui

9:51:35 AM: publish: /opt/build/repo/build

[ehmicky]

Hi @kennymanman,

This is a different problem, unrelated to the CI issue mentioned above.
The build logs show the following:

9:51:30 AM: Cannot find module: ‘react-router-dom’. Make sure this package is installed.
9:51:30 AM: You can install this package by running: npm install react-router-dom.

Installing this dependency with npm install react-router-dom should fix it.

[Allislove]

Thanks, Gracias, this works for me.

[moscuet]

@ehmicky
Hello, I am in trouble with same problem as well. I have followed your instructions but still same problem.
6:08:20 PM: Waiting for other deploys from your team to complete

6:14:14 PM: Build ready to start

6:14:16 PM: build-image version: b0258b965567defc4a2d7e2f2dec2e00c8f73ad6

6:14:16 PM: build-image tag: v3.4.1

6:14:16 PM: buildbot version: fcbc7a79f7372e5995cf02954ef19fc48d20c871

6:14:16 PM: Fetching cached dependencies

6:14:16 PM: Failed to fetch cache, continuing with build

6:14:16 PM: Starting to prepare the repo for build

6:14:16 PM: No cached dependencies found. Cloning fresh repo

6:14:16 PM: git clone GitHub - moscuet/pomodoro-clock

6:14:17 PM: Preparing Git Reference refs/heads/master

6:14:18 PM: Different publish path detected, going to use the one specified in the Netlify configuration file: ‘build’ versus ‘build/’ in the Netlify UI

6:14:18 PM: Starting build script

6:14:18 PM: Installing dependencies

6:14:18 PM: Python version set to 2.7

6:14:19 PM: v12.18.0 is already installed.

6:14:20 PM: Now using node v12.18.0 (npm v6.14.4)

6:14:20 PM: Started restoring cached build plugins

6:14:20 PM: Finished restoring cached build plugins

6:14:20 PM: Attempting ruby version 2.7.1, read from environment

6:14:21 PM: Using ruby version 2.7.1

6:14:22 PM: Using PHP version 5.6

6:14:22 PM: 5.2 is already installed.

6:14:22 PM: Using Swift version 5.2

6:14:22 PM: Started restoring cached node modules

6:14:22 PM: Finished restoring cached node modules

6:14:22 PM: Installing NPM modules using NPM version 6.14.4

6:14:49 PM: > core-js@2.6.11 postinstall /opt/build/repo/node_modules/babel-runtime/node_modules/core-js

6:14:49 PM: > node -e “try{require(‘./postinstall’)}catch(e){}”

6:14:50 PM: > core-js@3.6.5 postinstall /opt/build/repo/node_modules/core-js

6:14:50 PM: > node -e “try{require(‘./postinstall’)}catch(e){}”

6:14:50 PM: > core-js-pure@3.6.5 postinstall /opt/build/repo/node_modules/core-js-pure

6:14:50 PM: > node -e “try{require(‘./postinstall’)}catch(e){}”

6:14:52 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/webpack-dev-server/node_modules/fsevents):

6:14:52 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

6:14:52 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/watchpack-chokidar2/node_modules/fsevents):

6:14:52 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

6:14:52 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/jest-haste-map/node_modules/fsevents):

6:14:52 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

6:14:52 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.1.2 (node_modules/fsevents):

6:14:52 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.1.2: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

6:14:52 PM: added 1610 packages from 802 contributors and audited 1617 packages in 29.198s

6:14:53 PM: 65 packages are looking for funding

6:14:53 PM: run npm fund for details

6:14:53 PM: found 0 vulnerabilities

6:14:53 PM: NPM modules installed

6:14:53 PM: Started restoring cached go cache

6:14:53 PM: Finished restoring cached go cache

6:14:53 PM: go version go1.14.4 linux/amd64

6:14:54 PM: go version go1.14.4 linux/amd64

6:14:54 PM: Installing missing commands

6:14:54 PM: Verify run directory

6:14:55 PM: ​

6:14:55 PM: ┌─────────────────────────────┐

6:14:55 PM: │ Netlify Build │

6:14:55 PM: └─────────────────────────────┘

6:14:55 PM: ​

6:14:55 PM: ❯ Version

6:14:55 PM: @netlify/build 3.3.0

6:14:55 PM: ​

6:14:55 PM: ❯ Flags

6:14:55 PM: deployId: 5f3e91e4fe514400e681a76a

6:14:55 PM: mode: buildbot

6:14:55 PM: ​

6:14:55 PM: ❯ Current directory

6:14:55 PM: /opt/build/repo

6:14:55 PM: ​

6:14:55 PM: ❯ Config file

6:14:55 PM: No config file was defined: using default values.

6:14:55 PM: ​

6:14:55 PM: ❯ Context

6:14:55 PM: production

6:14:55 PM: ​

6:14:55 PM: ┌───────────────────────────────────┐

6:14:55 PM: │ 1. Build command from Netlify app │

6:14:55 PM: └───────────────────────────────────┘

6:14:55 PM: ​

6:14:55 PM: $ CI= npm run build

6:14:55 PM: > my-app@0.1.0 build /opt/build/repo

6:14:55 PM: > react-scripts build

6:14:56 PM: Creating an optimized production build…

6:15:08 PM: Failed to compile.

6:15:08 PM:

6:15:08 PM: ./src/component/timer/timer.module.scss

6:15:08 PM: To import Sass files, you first need to install node-sass.

6:15:08 PM: Run npm install node-sass or yarn add node-sass inside your workspace.

6:15:08 PM: Require stack:

6:15:08 PM: - /opt/build/repo/node_modules/sass-loader/dist/getDefaultSassImplementation.js

6:15:08 PM: - /opt/build/repo/node_modules/sass-loader/dist/getSassImplementation.js

6:15:08 PM: - /opt/build/repo/node_modules/sass-loader/dist/index.js

6:15:08 PM: - /opt/build/repo/node_modules/sass-loader/dist/cjs.js

6:15:08 PM: - /opt/build/repo/node_modules/loader-runner/lib/loadLoader.js

6:15:08 PM: - /opt/build/repo/node_modules/loader-runner/lib/LoaderRunner.js

6:15:08 PM: - /opt/build/repo/node_modules/webpack/lib/NormalModule.js

6:15:08 PM: - /opt/build/repo/node_modules/webpack/lib/NormalModuleFactory.js

6:15:08 PM: - /opt/build/repo/node_modules/webpack/lib/Compiler.js

6:15:08 PM: - /opt/build/repo/node_modules/webpack/lib/webpack.js

6:15:08 PM: - /opt/build/repo/node_modules/react-scripts/scripts/build.js

6:15:08 PM: npm ERR! code ELIFECYCLE

6:15:08 PM: npm ERR! errno 1

6:15:08 PM: npm ERR! my-app@0.1.0 build: react-scripts build

6:15:08 PM: npm ERR! Exit status 1

6:15:08 PM: npm ERR!

6:15:08 PM: npm ERR! Failed at the my-app@0.1.0 build script.

6:15:08 PM: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

6:15:08 PM: npm ERR! A complete log of this run can be found in:

6:15:08 PM: npm ERR! /opt/buildhome/.npm/_logs/2020-08-20T15_15_08_851Z-debug.log

6:15:08 PM:

6:15:08 PM: If the build failed with a warning about “process.env.CI = true”, this is due to “create-react-app” treating warnings as errors when in CI. In order to fix this problem, please either:

6:15:08 PM: - Fix the issues highlighted by the warnings above.

6:15:08 PM: - Or modify the “scripts.build” command in your “package.json” from “react-scripts build” to “CI= react-scripts build”

6:15:08 PM: More information can be found at Build troubleshooting tips | Netlify Docs

6:15:08 PM: ​

6:15:08 PM: ┌─────────────────────────────┐

6:15:08 PM: │ “build.command” failed │

6:15:08 PM: └─────────────────────────────┘

6:15:08 PM: ​

6:15:08 PM: Error message

6:15:08 PM: Command failed with exit code 1: CI= npm run build

6:15:08 PM: ​

6:15:08 PM: Error location

6:15:08 PM: In Build command from Netlify app:

6:15:08 PM: CI= npm run build

6:15:08 PM: ​

6:15:08 PM: Resolved config

6:15:08 PM: build:

6:15:08 PM: command: CI= npm run build

6:15:08 PM: commandOrigin: ui

6:15:08 PM: publish: /opt/build/repo/build

6:15:08 PM: Caching artifacts

6:15:08 PM: Started saving node modules

6:15:08 PM: Finished saving node modules

6:15:08 PM: Started saving build plugins

6:15:08 PM: Finished saving build plugins

6:15:08 PM: Started saving pip cache

6:15:09 PM: Finished saving pip cache

6:15:09 PM: Started saving emacs cask dependencies

6:15:09 PM: Finished saving emacs cask dependencies

6:15:09 PM: Started saving maven dependencies

6:15:09 PM: Finished saving maven dependencies

6:15:09 PM: Started saving boot dependencies

6:15:09 PM: Finished saving boot dependencies

6:15:09 PM: Started saving go dependencies

6:15:09 PM: Finished saving go dependencies

6:15:11 PM: Error running command: Build script returned non-zero exit code: 1

6:15:11 PM: Failing build: Failed to build site

6:15:11 PM: Failed during stage ‘building site’: Build script returned non-zero exit code: 1

6:15:11 PM: Finished processing build request in 55.552910822s

[perry]

this error is occurring because your project requires a package to process sass files and you don’t seem to be installing one on build.

6:15:08 PM: ./src/component/timer/timer.module.scss

6:15:08 PM: To import Sass files, you first need to install node-sass.

6:15:08 PM: Run npm install node-sass or yarn add node-sass inside your workspace.

if you don’t have node-sass listed in your package.json, you’ll have to add it.

[sarafotros]

I had the same problem and I changed the scripts.bulid to “CI= react-scripts build”, now it deployed the app but the link does’t show me anything. I am using the https://app.netlify.com/ for deployment

[perry]

hey there, which site is this regarding? can we take a look?

[sarafotros]

yeah, it is a react app. do you want me to send you the repository on github?

[perry]

i think that seeing the live site you have deployed would be helpful, primarily!

[ticklu1990]

There are issues even after the CI= npm run build.Can anyone help:
----------------------------------------------------------------------------=------------

Deploy Log:
10:01:00 PM: Build ready to start
10:01:02 PM: build-image version: 09c2cdcdf242cf2f57c9ee0fcad9d298fad9ad41
10:01:02 PM: build-image tag: v3.5.0
10:01:02 PM: buildbot version: 172aa31cb336bae73f9eb30159b9f95fe46f2e63
10:01:02 PM: Fetching cached dependencies
10:01:02 PM: Starting to download cache of 122.4MB
10:01:03 PM: Finished downloading cache in 1.423648506s
10:01:03 PM: Starting to extract cache
10:01:09 PM: Finished extracting cache in 5.480054992s
10:01:09 PM: Finished fetching cache in 6.9410409s
10:01:09 PM: Starting to prepare the repo for build
10:01:09 PM: Preparing Git Reference refs/heads/main
10:01:11 PM: Different publish path detected, going to use the one specified in the Netlify configuration file: ‘build’ versus ‘build/’ in the Netlify UI
10:01:11 PM: Starting build script
10:01:11 PM: Installing dependencies
10:01:11 PM: Python version set to 2.7
10:01:11 PM: Started restoring cached node version
10:01:14 PM: Finished restoring cached node version
10:01:14 PM: v12.18.0 is already installed.
10:01:15 PM: Now using node v12.18.0 (npm v6.14.4)
10:01:15 PM: Started restoring cached build plugins
10:01:15 PM: Finished restoring cached build plugins
10:01:15 PM: Attempting ruby version 2.7.1, read from environment
10:01:17 PM: Using ruby version 2.7.1
10:01:17 PM: Using PHP version 5.6
10:01:17 PM: Started restoring cached node modules
10:01:17 PM: Finished restoring cached node modules
10:01:17 PM: Started restoring cached go cache
10:01:17 PM: Finished restoring cached go cache
10:01:18 PM: go version go1.14.4 linux/amd64
10:01:18 PM: go version go1.14.4 linux/amd64
10:01:18 PM: Installing missing commands
10:01:18 PM: Verify run directory
10:01:19 PM: ​
10:01:19 PM: ────────────────────────────────────────────────────────────────
10:01:19 PM: Netlify Build
10:01:19 PM: ────────────────────────────────────────────────────────────────
10:01:19 PM: ​
10:01:19 PM: ❯ Version
10:01:19 PM: @netlify/build 5.3.2
10:01:19 PM: ​
10:01:19 PM: ❯ Flags
10:01:19 PM: deployId: 5fbd35447226f838cbe34d9c
10:01:19 PM: mode: buildbot
10:01:19 PM: ​
10:01:19 PM: ❯ Current directory
10:01:19 PM: /opt/build/repo
10:01:19 PM: ​
10:01:19 PM: ❯ Config file
10:01:19 PM: No config file was defined: using default values.
10:01:19 PM: ​
10:01:19 PM: ❯ Context
10:01:19 PM: production
10:01:19 PM: ​
10:01:19 PM: ────────────────────────────────────────────────────────────────
10:01:19 PM: 1. Build command from Netlify app
10:01:19 PM: ────────────────────────────────────────────────────────────────
10:01:19 PM: ​
10:01:19 PM: $ CI= npm run build
10:01:20 PM: > tutorville@0.1.0 build /opt/build/repo
10:01:20 PM: > react-scripts build
10:01:21 PM: Creating an optimized production build…
10:01:34 PM: Compiled with warnings.
10:01:34 PM:
10:01:34 PM: src/reducer.js
10:01:34 PM: Line 29:32: Expected ‘===’ and instead saw ‘==’ eqeqeq
10:01:34 PM: Line 43:32: Expected ‘===’ and instead saw ‘==’ eqeqeq
10:01:34 PM: src/redux/TaskList.js
10:01:34 PM: Line 13:19: ‘setIsInput’ is assigned a value but never used no-unused-vars
10:01:34 PM: Line 70:26: Expected ‘===’ and instead saw ‘==’ eqeqeq
10:01:34 PM: Line 77:42: Expected ‘===’ and instead saw ‘==’ eqeqeq
10:01:34 PM: src/store.js
10:01:34 PM: Line 2:38: ‘applyMiddleware’ is defined but never used no-unused-vars
10:01:34 PM: src/util/taskId.js
10:01:34 PM: Line 3:1: Unexpected default export of anonymous function import/no-anonymous-default-export
10:01:34 PM: Search for the keywords to learn more about each warning.
10:01:34 PM: To ignore, add // eslint-disable-next-line to the line before.
10:01:34 PM: File sizes after gzip:
10:01:34 PM: 80.27 KB build/static/js/2.59b532d0.chunk.js
10:01:34 PM: 22.49 KB build/static/css/2.1a02f21c.chunk.css
10:01:34 PM: 1.99 KB build/static/js/main.7452051d.chunk.js
10:01:34 PM: 1.39 KB build/static/js/3.f9a4f7d7.chunk.js
10:01:34 PM: 1.17 KB build/static/js/runtime-main.73e2dc2b.js
10:01:34 PM: 577 B build/static/css/main.1aad4dcf.chunk.css
10:01:34 PM: The project was built assuming it is hosted at /tutorville/.
10:01:34 PM: You can control this with the homepage field in your package.json.
10:01:34 PM: The build folder is ready to be deployed.
10:01:34 PM: Find out more about deployment here:
10:01:34 PM: Deployment | Create React App
10:01:35 PM: ​
10:01:35 PM: (build.command completed in 15.2s)
10:01:35 PM: ​
10:01:35 PM: ────────────────────────────────────────────────────────────────
10:01:35 PM: Netlify Build Complete
10:01:35 PM: ────────────────────────────────────────────────────────────────
10:01:35 PM: ​
10:01:35 PM: (Netlify Build completed in 15.3s)
10:01:35 PM: Caching artifacts
10:01:35 PM: Started saving node modules
10:01:35 PM: Finished saving node modules
10:01:35 PM: Started saving build plugins
10:01:35 PM: Finished saving build plugins
10:01:35 PM: Started saving pip cache
10:01:35 PM: Finished saving pip cache
10:01:35 PM: Started saving emacs cask dependencies
10:01:35 PM: Finished saving emacs cask dependencies
10:01:35 PM: Started saving maven dependencies
10:01:35 PM: Finished saving maven dependencies
10:01:35 PM: Started saving boot dependencies
10:01:35 PM: Finished saving boot dependencies
10:01:35 PM: Started saving go dependencies
10:01:35 PM: Finished saving go dependencies
10:01:35 PM: Build script success
10:01:35 PM: Starting to deploy site from ‘build’
10:01:35 PM: Creating deploy tree
10:01:35 PM: Creating deploy upload records
10:01:35 PM: 0 new files to upload
10:01:35 PM: 0 new functions to upload
10:01:35 PM: Starting post processing
10:01:35 PM: Post processing - HTML
10:01:35 PM: Post processing - header rules
10:01:35 PM: Post processing - redirect rules
10:01:35 PM: Post processing done
10:01:35 PM: Site is live
10:01:55 PM: Finished processing build request in 53.334987111s

Github repo for this code:

GitHub - ticklu1990/tutorville: A Online Study Portal

[ticklu1990]

Console Log:

[fool]

Seems like you are perhaps running into this situation?

[Support Guide] Why do I see “Uncaught SyntaxError: Unexpected token <” errors? How can I use chunking or versioning for my assets at Netlify?

Last reviewed by Netlify Support on December 2022 The error Uncaught SyntaxError: Unexpected token < is most commonly caused by your site’s code referring to an asset that is no longer available. Most commonly, this is due to a filename change in assets generated during your build. The same situation happens if you use versioned or chunked javascript where the filename changes with every deploy. Let’s look at an example: A file that was named /assets/main-123abc.js would change to /assets…

Many of those URL’s have asset fingerprints or hashes in them, and older content already loaded can refer back to files that do not exist in your current deploy.

[zourdycodes]

This is my deploy log, I have tried many ways to fix this by using your examples nevertheless always been failed to compile all the time. I know there is a message that my Header can’t found in my ‘./components’ in ‘./src’ files but my header is always been there Please, Help me Sir/ Madam

6:11:30 PM: Build ready to start
6:11:32 PM: build-image version: d84c79427e8f83c1ba17bcdd7b3fe38059376b68
6:11:32 PM: build-image tag: v3.6.1
6:11:32 PM: buildbot version: d35018babe252245044d3565f193fa426818b4b1
6:11:32 PM: Fetching cached dependencies
6:11:32 PM: Failed to fetch cache, continuing with build
6:11:32 PM: Starting to prepare the repo for build
6:11:32 PM: No cached dependencies found. Cloning fresh repo
6:11:32 PM: git clone https://github.com/zourdycodes/personal-website
6:11:35 PM: Preparing Git Reference refs/heads/master
6:11:36 PM: Different publish path detected, going to use the one specified in the Netlify configuration file: ‘build’ versus ‘build/’ in the Netlify UI
6:11:37 PM: Starting build script
6:11:37 PM: Installing dependencies
6:11:37 PM: Python version set to 2.7
6:11:38 PM: v12.18.0 is already installed.
6:11:39 PM: Now using node v12.18.0 (npm v6.14.4)
6:11:39 PM: Started restoring cached build plugins
6:11:39 PM: Finished restoring cached build plugins
6:11:39 PM: Attempting ruby version 2.7.1, read from environment
6:11:40 PM: Using ruby version 2.7.1
6:11:41 PM: Using PHP version 5.6
6:11:41 PM: Started restoring cached node modules
6:11:41 PM: Finished restoring cached node modules
6:11:41 PM: Installing NPM modules using NPM version 6.14.4
6:12:15 PM: npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but package-lock.json was generated for lockfileVersion@2. I’ll try to do my best with it!
6:12:15 PM: > core-js@2.6.12 postinstall /opt/build/repo/node_modules/babel-runtime/node_modules/core-js
6:12:15 PM: > node -e “try{require(‘./postinstall’)}catch(e){}”
6:12:15 PM: > core-js@3.8.3 postinstall /opt/build/repo/node_modules/core-js
6:12:15 PM: > node -e “try{require(‘./postinstall’)}catch(e){}”
6:12:15 PM: > core-js-pure@3.8.3 postinstall /opt/build/repo/node_modules/core-js-pure
6:12:15 PM: > node -e “try{require(‘./postinstall’)}catch(e){}”
6:12:15 PM: > ejs@2.7.4 postinstall /opt/build/repo/node_modules/ejs
6:12:15 PM: > node ./postinstall.js
6:12:18 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/webpack-dev-server/node_modules/fsevents):
6:12:18 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
6:12:18 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/watchpack-chokidar2/node_modules/fsevents):
6:12:18 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
6:12:18 PM: npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.3.1 (node_modules/fsevents):
6:12:18 PM: npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.3.1: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
6:12:18 PM: added 1984 packages from 920 contributors and audited 1990 packages in 36.768s
6:12:20 PM: 125 packages are looking for funding
6:12:20 PM: run npm fund for details
6:12:20 PM: found 0 vulnerabilities
6:12:20 PM: NPM modules installed
6:12:20 PM: Started restoring cached go cache
6:12:20 PM: Finished restoring cached go cache
6:12:20 PM: go version go1.14.4 linux/amd64
6:12:20 PM: go version go1.14.4 linux/amd64
6:12:20 PM: Installing missing commands
6:12:20 PM: Verify run directory
6:12:22 PM: ​
6:12:22 PM: ────────────────────────────────────────────────────────────────
6:12:22 PM: Netlify Build
6:12:22 PM: ────────────────────────────────────────────────────────────────
6:12:22 PM: ​
6:12:22 PM: ❯ Version
6:12:22 PM: @netlify/build 9.0.0
6:12:22 PM: ​
6:12:22 PM: ❯ Flags
6:12:22 PM: deployId: 601d27e20aa75ddb3194cb27
6:12:22 PM: mode: buildbot
6:12:22 PM: ​
6:12:22 PM: ❯ Current directory
6:12:22 PM: /opt/build/repo
6:12:22 PM: ​
6:12:22 PM: ❯ Config file
6:12:22 PM: No config file was defined: using default values.
6:12:22 PM: ​
6:12:22 PM: ❯ Context
6:12:22 PM: production
6:12:22 PM: ​
6:12:22 PM: ────────────────────────────────────────────────────────────────
6:12:22 PM: 1. Build command from Netlify app
6:12:22 PM: ────────────────────────────────────────────────────────────────
6:12:22 PM: ​
6:12:22 PM: $ CI= npm run build
6:12:23 PM: > portfolio-web@0.1.0 build /opt/build/repo
6:12:23 PM: > react-scripts build
6:12:24 PM: Creating an optimized production build…
6:12:28 PM: Failed to compile.
6:12:28 PM:
6:12:28 PM: ./src/App.js
6:12:28 PM: Cannot find file ‘./components/header’ in ‘./src’.
6:12:28 PM: npm ERR! code ELIFECYCLE
6:12:28 PM: npm ERR! errno 1
6:12:28 PM: npm ERR! portfolio-web@0.1.0 build: react-scripts build
6:12:28 PM: npm ERR! Exit status 1
6:12:28 PM: npm ERR!
6:12:28 PM: npm ERR! Failed at the portfolio-web@0.1.0 build script.
6:12:28 PM: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
6:12:28 PM: npm ERR! A complete log of this run can be found in:
6:12:28 PM: npm ERR! /opt/buildhome/.npm/_logs/2021-02-05T11_12_28_722Z-debug.log
6:12:28 PM: ​
6:12:28 PM: ────────────────────────────────────────────────────────────────
6:12:28 PM: “build.command” failed
6:12:28 PM: ────────────────────────────────────────────────────────────────
6:12:28 PM: ​
6:12:28 PM: Error message
6:12:28 PM: Command failed with exit code 1: CI= npm run build
6:12:28 PM: ​
6:12:28 PM: Error location
6:12:28 PM: In Build command from Netlify app:
6:12:28 PM: CI= npm run build
6:12:28 PM: ​
6:12:28 PM: Resolved config
6:12:28 PM: build:
6:12:28 PM: command: CI= npm run build
6:12:28 PM: commandOrigin: ui
6:12:28 PM: publish: /opt/build/repo/build
6:12:28 PM: Caching artifacts
6:12:28 PM: Started saving node modules
6:12:28 PM: Finished saving node modules
6:12:28 PM: Started saving build plugins
6:12:28 PM: Finished saving build plugins
6:12:28 PM: Started saving pip cache
6:12:29 PM: Finished saving pip cache
6:12:29 PM: Started saving emacs cask dependencies
6:12:29 PM: Finished saving emacs cask dependencies
6:12:29 PM: Started saving maven dependencies
6:12:29 PM: Finished saving maven dependencies
6:12:29 PM: Started saving boot dependencies
6:12:29 PM: Finished saving boot dependencies
6:12:29 PM: Started saving rust rustup cache
6:12:29 PM: Finished saving rust rustup cache
6:12:29 PM: Started saving go dependencies
6:12:29 PM: Finished saving go dependencies
6:12:32 PM: Build failed due to a user error: Build script returned non-zero exit code: 2
6:12:32 PM: Failing build: Failed to build site
6:12:32 PM: Failed during stage ‘building site’: Build script returned non-zero exit code: 2
6:12:32 PM: Finished processing build request in 59.670462729s

[perry]

@zourdycodes

6:12:28 PM: Failed to compile.
6:12:28 PM:
6:12:28 PM: ./src/App.js
6:12:28 PM: Cannot find file ‘./components/header’ in ‘./src’.
6:12:28 PM: npm ERR! code ELIFECYCLE

so, basically, the file “header” in the subfolder “components” in the folder “src” can’t be found.

You’ll want to check your paths, and evalate whether case is part of the problem:

[Support Guide] Netlify app builds locally but fails on deploy (case sensitivity)

Last Reviewed By Netlify Support Staff: December 2022 Are you struggling to understand why your project runs locally but errors out with missing files or logs that point toward issues with case when you try and build on Netlify? You are not alone. Often, case (as in: UPPERCASE or lowercase letters in filenames or paths) can cause problems. Here is a guide to understanding how case sensitivity issues present themselves, why they arise, and how you can fix them! 1. Errors you might see Case sens…

[mahijendra]

I tried the solutions you posted, but i am still seeing the error

Retrieving list of deployment files…
21:09:18.671 Downloading 63 deployment files…
21:09:19.268 Analyzing source code…
21:09:19.729 Installing build runtime…
21:09:21.795 Build runtime installed: 2066.017ms
21:09:23.506 Looking up build cache…
21:09:23.556 Build cache not found
21:09:24.257 Detected package.json
21:09:24.257 Installing dependencies…
21:09:24.732 npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but package-lock.json was generated for lockfileVersion@2. I’ll try to do my best with it!
21:09:52.465 > core-js@2.6.12 postinstall /vercel/workpath0/node_modules/babel-runtime/node_modules/core-js
21:09:52.465 > node -e “try{require(’./postinstall’)}catch(e){}”
21:09:52.566 > core-js@3.9.1 postinstall /vercel/workpath0/node_modules/core-js
21:09:52.566 > node -e “try{require(’./postinstall’)}catch(e){}”
21:09:52.634 > core-js-pure@3.9.1 postinstall /vercel/workpath0/node_modules/core-js-pure
21:09:52.634 > node -e “try{require(’./postinstall’)}catch(e){}”
21:09:52.719 > ejs@2.7.4 postinstall /vercel/workpath0/node_modules/ejs
21:09:52.719 > node ./postinstall.js
21:09:54.562 npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/webpack-dev-server/node_modules/fsevents):
21:09:54.562 npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
21:09:54.569 npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules/watchpack-chokidar2/node_modules/fsevents):
21:09:54.569 npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
21:09:54.577 npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.3.2 (node_modules/fsevents):
21:09:54.577 npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.3.2: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
21:09:54.584 added 1954 packages from 787 contributors in 29.891s
21:09:55.725 135 packages are looking for funding
21:09:55.725 run npm fund for details
21:09:55.955 Running “npm run build”
21:09:56.162 > spotify-clone@0.1.0 build /vercel/workpath0
21:09:56.162 > react-scripts build
21:09:57.520 Creating an optimized production build…
21:10:19.203 Treating warnings as errors because process.env.CI = true.
21:10:19.203 Most CI servers set it automatically.
21:10:19.203 Failed to compile.
21:10:19.204 src/Footer.js
21:10:19.204 Line 1:28: ‘useState’ is defined but never used no-unused-vars
21:10:19.204 Line 15:12: ‘token’ is assigned a value but never used no-unused-vars
21:10:19.204 Line 31:6: React Hook useEffect has a missing dependency: ‘dispatch’. Either include it or remove the dependency array react-hooks/exhaustive-deps
21:10:19.204 src/Header.js
21:10:19.204 Line 6:10: ‘useEffect’ is defined but never used no-unused-vars
21:10:19.204 Line 9:20: ‘dispatch’ is assigned a value but never used no-unused-vars
21:10:19.204 src/Sidebar.js
21:10:19.204 Line 7:10: ‘getTokenFromResponse’ is defined but never used no-unused-vars
21:10:19.204 Line 11:25: ‘dispatch’ is assigned a value but never used no-unused-vars
21:10:19.204 src/reducer.js
21:10:19.204 Line 1:10: ‘findAllByDisplayValue’ is defined but never used no-unused-vars
21:10:19.235 npm ERR! code ELIFECYCLE
21:10:19.235 npm ERR! errno 1
21:10:19.238 npm ERR! spotify-clone@0.1.0 build: react-scripts build
21:10:19.239 npm ERR! Exit status 1
21:10:19.239 npm ERR!
21:10:19.239 npm ERR! Failed at the spotify-clone@0.1.0 build script.
21:10:19.239 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
21:10:19.253 npm ERR! A complete log of this run can be found in:
21:10:19.253 npm ERR! /vercel/.npm/_logs/2021-03-08T15_40_19_239Z-debug.log
21:10:19.259 Error: Command “npm run build” exited with 1
21:10:21.979 Done with “package.json”

I’ve been trying to find the solution for almost 2 days now
Some please help me out.

[perry]

hi there, this guide will undeniably be helpful!

New CI=true build configuration, "Treating warnings as errors because process.env.CI = true"

Beginning on June 15, 2020 Netlify will start a gradual rollout of adding the environment variable CI to build environments, with the value of true . This environment variable, short for Continuous Integration, is commonly set in various CI environments like Travis CI and Github Actions, among many others. The ecosystem has largely agreed to use this environment setting to detect when a build is executing in a CI environment, as opposed to a local development environment. This setting allows…

[linkon63]

Thank You… I have solved my problem

[alfredrafael]

Running npm install react-router-dom WORKED FOR ME AS WELL Thank youuuuu