understand package installation errors | Angular Community | Page 1

edgy sapphire Jul 15, 2025, 5:49 AM

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package.json

{
  "dependencies": {
...
    "@angular/material": "~20.0.5",
    "@angular/material-moment-adapter": "^20.0.5",

ng add @angular-eslint/schematics -f

npm error code ERESOLVE
npm error ERESOLVE could not resolve
npm error
npm error While resolving: @angular/material-moment-adapter@20.1.0
npm error Found: @angular/material@20.0.6
npm error node_modules/@angular/material
npm error   @angular/material@"~20.0.5" from the root project
npm error
npm error Could not resolve dependency:
npm error peer @angular/material@"20.1.0" from @angular/material-moment-adapter@20.1.0
npm error node_modules/@angular/material-moment-adapter
npm error   @angular/material-moment-adapter@"^20.0.5" from the root project
npm error
npm error Conflicting peer dependency: @angular/material@20.1.0
npm error node_modules/@angular/material
npm error   peer @angular/material@"20.1.0" from @angular/material-moment-adapter@20.1.0
npm error   node_modules/@angular/material-moment-adapter
npm error     @angular/material-moment-adapter@"^20.0.5" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.

I put "-f", why does it refuse to install it?
what is the relationship between eslint and material?
can you help me understand what these errors mean? and how to resolve ?

proven basalt Jul 15, 2025, 6:12 AM

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You're mixing ^ (use latest minor version) and ~ (use latest patch version) for things that should have the same version number. So one is updated to 20.1.0 but the other can't, thus causing dependency conflicts.

edgy sapphire Jul 15, 2025, 6:21 AM

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ok but I didn't ask to install version 20.1.0 of moment ..
I want to install eslint
That’s what I don’t understand?

proven basalt Jul 15, 2025, 6:24 AM

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I don't know npm and the ng add command well enough to know precisely when they decide to resolve new dependencies, but they do. And since you used ^ and ~ rather than fixed versions, you accepted to install newer versions.

edgy sapphire Jul 15, 2025, 6:27 AM

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OK thanks
so it is recommended to put ~ everywhere in package.json instead of ^
so that it installs corrected versions?

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so I delete the node_modules folder
replace ^ with ~
npm i

proven basalt Jul 15, 2025, 6:46 AM

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No. It's recommended to be consistent and logical.
If you want, for a group of dependencies that must always have the same version number (like material and material-moment-adapter) to automatically upgrade to the latest minor version, then use ^, consistently.
If you want to automatically upgrade to the latest patch version, then use ~, consistently.
If you want to avoid automatic upgrades and be in control of when and what to upgrade, use fixed version numbers.

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