unable to resolve dependency tree error for creating new angular project

Question

so today I wanted to create a new Angular project using the command ng new <projectname> and I got this error:

npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: [email protected]
npm ERR! Found: [email protected]
npm ERR! node_modules/jasmine-core
npm ERR!   dev jasmine-core@"~3.6.0" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer jasmine-core@">=3.7.1" from [email protected]
npm ERR! node_modules/karma-jasmine-html-reporter
npm ERR!   dev karma-jasmine-html-reporter@"^1.5.0" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.

---

I literally tried everything, I updated npm, installed Angular cli again, download and installed node again, npm audit, and a lot of other things but nothing happened.

Also as you can see error told me to use the command with --force, I tried but nothing happened, and with --legacy-peer-deps, I get the error as unknown option.

What is bothering me the most is that everything was working completely right last night and I changed nothing at all but suddenly I'm getting this error today.

Answer 1

Open the folder you create with ng new and open the package.json file. In devDependencies change the version of "jasmine-core" 3.6.0 to 3.8.0 and "karma-jasmine-html-reporter" from 1.7.0 to 1.6.0 and save it. Then go back to Terminal and go to your project and run npm install. Now it works and you can run ng serve.

Edit 2021

"jasmine-core": "~3.8.0",
"karma-jasmine-html-reporter": "^1.7.0"

Answer 2

Mine is a temporary solution for angular-cli v11.2.12 based on @david-Öztürk answer and on this angular-cli github issue discussions and on its merged fix.

By executing the steps listed on @david-Öztürk answer I was still getting the same error. And also the fix is more conservative than the proposed solution. I hope it helps someone else:

Run the Angular project creation without automatic npm packages installation:

ng new --skip-install <project-name>

Enter project directory:

cd <project-name>

Edit package.json and change this...

"karma-jasmine-html-reporter": "^1.5.0",

...to this:

"karma-jasmine-html-reporter": "~1.5.0",

Manually install npm packages:

npm install

Note: The version 1.5.0 here was used because it is the version that appears in the error message and we are tying to be more conservative here. Please adapt the version according to your specific necessity. For newer projects the version 1.7.0 may be more suited but it can change with time. Read your specific error message in order to chose what better addresses your specific case.

Answer 3

I had the same problem and I solved it with reinstalling nodeJs 14.16.1 but I had to change the version of npm manually with the command

npm install -g [email protected]

After of course, I tested the modifications by creating a project

ng new <MyProjet>

Answer 4

If you are still facing this problem then try to make sure your package.json have all versions matching other supporting library versions. The jasmine-core had to be greater than 3.8 with karma-jasmine-html-report 1.7+

here is how my devDependecies looked inside package.json

"devDependencies": {
    "@angular-devkit/build-angular": "~12.0.0",
    "@angular/cli": "~12.0.0",
    "@angular/compiler-cli": "~12.0.0",
    "@types/jasmine": "~3.6.0",
    "@types/node": "^12.11.1",
    "jasmine-core": "~3.8.0",
    "karma": "~6.3.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.0.3",
    "karma-jasmine": "~4.0.0",
    "karma-jasmine-html-reporter": "^1.7.0",
    "typescript": "~4.2.3"
  }

Answer 5

Looks like the issue with latest NPM 7.12.0 and the latest Node 16.1.0(Current Version)

In my case I followed the below steps -

1. Uninstall Node
2. Re-Install the Latest Node (LTS: 14.16.1)
   • Which will install the latest NPM : 6.14.12
3. Run the ng new my-app

Answer 6

install node, if you do not have it or update to the newest version: https://nodejs.org/en/download/package-manager/

update your npm: npm install npm@latest -g

optional : npm i update-node

This will update angular to its newest version: npm install -g @angular/cli Create a new angular project: ng new projectName Change directory the projectName: cd projectName Serve the project ng s

Answer 7

What it worked for me was manually update package.json to look like this

"jasmine-core": "~3.8.0",
"karma-jasmine-html-reporter": "^1.7.0"

and then I tried

npm install

but didn't work either so I tried

npm install --legacy-peer-deps

and then everything worked again I was able to do npm start as usual