fix(@angular-devkit/build-angular): pass system path to readTsconfig

Author: filipesilva

packages/angular_devkit/build_angular/src/angular-cli-files/utilities/read-tsconfig.ts

@@ -16,5 +16,13 @@ export function readTsconfig(tsconfigPath: string) {
   const configResult = projectTs.readConfigFile(tsconfigPath, projectTs.sys.readFile);
   const tsConfig = projectTs.parseJsonConfigFileContent(configResult.config, projectTs.sys,
     path.dirname(tsconfigPath), undefined, tsconfigPath);
+
+  if (tsConfig.errors.length > 0) {
+    throw new Error(
+      `Errors found while reading ${tsconfigPath}:\n  ${
+        tsConfig.errors.map(e => e.messageText).join('\n  ')
+      }`
+    )
+  }
   return tsConfig;
 }

packages/angular_devkit/build_angular/src/browser/index.ts

@@ -13,6 +13,7 @@ import {
 import { BuildResult, WebpackLoggingCallback, runWebpack } from '@angular-devkit/build-webpack';
 import {
   experimental,
+  getSystemPath,
   join,
   json,
   logging,
@@ -185,7 +186,7 @@ export function buildWebpackBrowser(
         normalize(workspace.getProject(projectName).root),
       );
 
-      const tsConfigPath = path.resolve(workspace.root, options.tsConfig);
+      const tsConfigPath = path.resolve(getSystemPath(workspace.root), options.tsConfig);
       const tsConfig = readTsconfig(tsConfigPath);
 
       if (isEs5SupportNeeded(projectRoot) &&