typescript - Updating Angular 8 to Angular 9 unable to resolve dependency tree

Question

I have been trying to update our Angular 8 to 9 except I keep running into an error about dependencies not being able to be resolved.

I tried updating the local CLI first but that gave me the same errors. My global CLI is updated as well. Running ng update @angular/cli@9 gives me the following error:

    Found: @angular-devkit/[email protected]
node_modules/@angular-devkit/build-angular
  dev @angular-devkit/build-angular@"^0.901.13" from the root project

Could not resolve dependency:
dev @angular-devkit/build-angular@"^0.901.13" from the root project

Conflicting peer dependency: @angular/[email protected]
node_modules/@angular/compiler-cli
  peer @angular/compiler-cli@">=9.0.0 < 10" from @angular-devkit/[email protected]
  node_modules/@angular-devkit/build-angular
    dev @angular-devkit/build-angular@"^0.901.13" from the root project

Following the Angular update tool doesn't seem of much help. How do I go about fixing this error?

question from:https://stackoverflow.com/questions/65919445/updating-angular-8-to-angular-9-unable-to-resolve-dependency-tree

Answer 1

I have no idea what causes the issue but running the exact same steps on a different machine solved it. Both machines run the same versions of node/npm/angular CLI etc. Cannot tell what the issue was.