message: fix(core): absOutputPath when config.outputPath is absolute
diff: import { chalk, lodash, yParser } from '@umijs/utils';
  import assert from 'assert';
  import { existsSync } from 'fs';
  -import { join } from 'path';
  +import { isAbsolute, join } from 'path';
  import { AsyncSeriesWaterfallHook } from '../../compiled/tapable';
  import { Config } from '../config/config';
  import { DEFAULT_FRAMEWORK_NAME } from '../constants';
  @@ -292,7 +292,9 @@ export class Service {
  });
  this.config = lodash.merge(defaultConfig, config) as Record<string, any>;
  if (this.config.outputPath) {
  - paths.absOutputPath = join(this.cwd, this.config.outputPath);
  + paths.absOutputPath = isAbsolute(this.config.outputPath)
  + ? this.config.outputPath
  + : join(this.cwd, this.config.outputPath);
  }
  this.paths = await this.applyPlugins({
  key: 'modifyPaths',
  