Angular 从 8 升级到 9 - 纱线不兼容错误

Question

I've upgraded the project from 8 to 9 as per angular.io upgrade guide But after the upgrade yarn install is giving this error. Does anyone know how to solve this?

Error:

error @angular-devkit/build-angular@0.901.4: The engine "yarn" is incompatible with this module. Expected version ">= 1.13.0". error Found incompatible module.

yarn install

warning @angular-devkit/build-angular > webpack-dev-server > chokidar > fsevents@1.2.12: fsevents 1 will break on node v14+ and could be using insecure binaries. Upgrade to fsevents 2.
warning @angular-devkit/build-angular > webpack > watchpack > chokidar@2.1.8: Chokidar 2 will break on node v14+. Upgrade to chokidar 3 with 15x less dependencies.
warning @angular-devkit/build-angular > stylus > css-parse > css > urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
warning @angular-devkit/build-angular > webpack > micromatch > snapdragon > source-map-resolve > urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
warning @angular-devkit/build-angular > webpack > micromatch > snapdragon > source-map-resolve > resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated
warning @angular/cli > universal-analytics > request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning karma > chokidar@2.1.8: Chokidar 2 will break on node v14+. Upgrade to chokidar 3 with 15x less dependencies.
warning karma > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning karma > log4js > circular-json@0.5.9: CircularJSON is in maintenance only, flatted is its successor.
[2/4] 🚚  Fetching packages...
error @angular-devkit/build-angular@0.901.4: The engine "yarn" is incompatible with this module. Expected version ">= 1.13.0".
error Found incompatible module
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

Answer 1

make sure you have a stable version of yarn https://classic.yarnpkg.com/en/docs/install/#windows-stable

i have installed yarn 1.22.4 and it worked