Unrevert "🏗 Update @percy/percy-puppeteer to v1.x (ampproject#25176)" (ampproject#25221)

* Revert "Revert "🏗 Update @percy/percy-puppeteer to v1.x (ampproject#25176)" (ampproject#25213)"

This reverts commit d134d30.

* Do not expect a build when running with --empty

Author: danielrozenberg

.gitignore

@@ -21,8 +21,6 @@ test/coverage
 *.swp
 *.swo
 yarn-error.log
-PERCY_BUILD_ID
-chromedriver.log
 sc-*-linux*
 sc-*-osx*
 sauce_connect_*

build-system/common/exec.js

@@ -21,8 +21,7 @@
 
 const childProcess = require('child_process');
 
-const shellCmd = process.platform == 'win32' ? 'cmd' : '/bin/sh';
-const shellFlag = process.platform == 'win32' ? '/C' : '-c';
+const shellCmd = process.platform == 'win32' ? 'cmd' : '/bin/bash';
 
 /**
  * Spawns the given command in a child process with the given options.
@@ -32,7 +31,7 @@ const shellFlag = process.platform == 'win32' ? '/C' : '-c';
  * @return {!Object}
  */
 function spawnProcess(cmd, options) {
-  return childProcess.spawnSync(shellCmd, [shellFlag, cmd], options);
+  return childProcess.spawnSync(cmd, Object.assign({shell: shellCmd}, options));
 }
 
 /**
@@ -56,7 +55,7 @@ function exec(cmd, options) {
  * @return {!Object}
  */
 function execScriptAsync(script, options) {
-  return childProcess.spawn(shellCmd, [shellFlag, script], options);
+  return childProcess.spawn(script, Object.assign({shell: shellCmd}, options));
 }
 
 /**

build-system/tasks/visual-diff/helpers.js

@@ -15,10 +15,10 @@
  */
 'use strict';
 
+const argv = require('minimist')(process.argv.slice(2));
 const colors = require('ansi-colors');
 const fancyLog = require('fancy-log');
 const sleep = require('sleep-promise');
-const {isTravisBuild} = require('../../common/travis');
 
 const CSS_SELECTOR_RETRY_MS = 200;
 const CSS_SELECTOR_RETRY_ATTEMPTS = 50;
@@ -54,10 +54,9 @@ function escapeHtml(html) {
 function log(mode, ...messages) {
   switch (mode) {
     case 'verbose':
-      if (isTravisBuild()) {
-        return;
+      if (argv.verbose) {
+        fancyLog.info(colors.green('VERBOSE:'), ...messages);
       }
-      fancyLog.info(colors.green('VERBOSE:'), ...messages);
       break;
     case 'info':
       fancyLog.info(colors.green('INFO:'), ...messages);
@@ -72,11 +71,6 @@ function log(mode, ...messages) {
       process.exitCode = 1;
       fancyLog.error(colors.red('FATAL:'), ...messages);
       throw new Error(messages.join(' '));
-    case 'travis':
-      if (isTravisBuild()) {
-        messages.forEach(message => process.stdout.write(message));
-      }
-      break;
   }
 }