error log

arya@arya-HP-Notebook:~$ cd Documents/opensource/oppia
arya@arya-HP-Notebook:~/Documents/opensource/oppia$ bash scripts/run_e2e_tests.sh 
Checking if node.js is installed in /home/arya/Documents/opensource/oppia_tools
Generating list of installed node modules...
Generation completed.
Checking whether Google App Engine is installed in /home/arya/Documents/opensource/oppia_tools/google_appengine_1.9.50/google_appengine
Environment setup completed.
Installing third-party JS libraries and zip files.
Checking whether eslint is installed
Checking whether eslint-plugin-html is installed
Checking whether gulp is installed
Checking whether through2 is installed
Checking whether yargs is installed
Checking whether gulp-concat is installed
Checking whether gulp-clean-css is installed
Checking whether gulp-util is installed
Checking whether gulp-sourcemaps is installed
Checking whether gulp-uglify is installed
Checking whether Skulpt is installed in third_party
Checking if pip is installed on the local machine
Checking if numpy is installed in /home/arya/Documents/opensource/oppia_tools/pip_packages
Checking if pylint is installed in /home/arya/Documents/opensource/oppia_tools/pip_packages
Checking if webtest is installed in third_party
Checking if browsermob-proxy is installed in /home/arya/Documents/opensource/oppia_tools/pip_packages
Checking if selenium is installed in /home/arya/Documents/opensource/oppia_tools/pip_packages
Installing pre-push hook for git
Symlink already exists

  Running build task with concatenation only 

[22:10:23] Using gulpfile ~/Documents/opensource/oppia/gulpfile.js
[22:10:23] Starting 'collectDependencyFilepaths'...
[22:10:23] Finished 'collectDependencyFilepaths' after 513 μs
[22:10:23] Starting 'generateCss'...
[22:10:23] Finished 'generateCss' after 19 ms
[22:10:23] Starting 'copyFonts'...
[22:10:23] Finished 'copyFonts' after 5.26 ms
[22:10:23] Starting 'generateJs'...
[22:10:23] Finished 'generateJs' after 18 ms
[22:10:23] Starting 'build'...
[22:10:23] Finished 'build' after 2.43 μs
Checking whether jasmine-core is installed
Checking whether karma is installed
Checking whether karma-jasmine is installed
Checking whether karma-jasmine-jquery is installed
Checking whether karma-json-fixtures-preprocessor is installed
Checking whether karma-coverage is installed
Checking whether karma-ng-html2js-preprocessor is installed
Checking whether karma-chrome-launcher is installed
Checking whether protractor is installed
Checking whether protractor-screenshot-reporter is installed
Checking whether jasmine-spec-reporter is installed
[22:10:24] I/update - chromedriver: file exists /home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/chromedriver_2.34.zip
[22:10:24] I/update - chromedriver: unzipping chromedriver_2.34.zip
[22:10:24] I/update - chromedriver: setting permissions to 0755 for /home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/chromedriver_2.34
[22:10:24] I/update - chromedriver: chromedriver_2.34 up to date
[22:10:24] I/update - selenium standalone: file exists /home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/selenium-server-standalone-3.8.1.jar
[22:10:24] I/update - selenium standalone: selenium-server-standalone-3.8.1.jar up to date
[22:10:28] I/update - geckodriver: file exists /home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/geckodriver-v0.19.1.tar.gz
[22:10:28] I/update - geckodriver: unzipping geckodriver-v0.19.1.tar.gz
[22:10:28] I/update - geckodriver: setting permissions to 0755 for /home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/geckodriver-v0.19.1
[22:10:28] I/update - geckodriver: geckodriver-v0.19.1 up to date
nc: connect to localhost port 8181 (tcp) failed: Connection refused
nc: connect to localhost port 4444 (tcp) failed: Connection refused
[22:10:28] I/start - java -Djava.security.egd=file:///dev/./urandom -Dwebdriver.chrome.driver=/home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/chromedriver_2.34 -Dwebdriver.gecko.driver=/home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/geckodriver-v0.19.1 -jar /home/arya/Documents/opensource/node_modules/protractor/node_modules/webdriver-manager/selenium/selenium-server-standalone-3.8.1.jar -port 4444
[22:10:28] I/start - seleniumProcess.pid: 11902
nc: connect to localhost port 4444 (tcp) failed: Connection refused
Connection to localhost 4444 port [tcp/*] succeeded!
Connection to localhost 9001 port [tcp/*] succeeded!
[22:10:30] I/launcher - Running 3 instances of WebDriver
.[22:10:39] I/testLogger - 
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[22:10:39] I/testLogger - [chrome #01-1] PID: 11951
[chrome #01-1] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/cacheSlugs.js
[chrome #01-1] 
[chrome #01-1] [22:10:31] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-1] Started
[chrome #01-1] Spec started
[chrome #01-1] .
[chrome #01-1]   Cache Slugs
[chrome #01-1]     ✓ should check that errors get logged for missing resources
[chrome #01-1] 
[chrome #01-1] 
[chrome #01-1] 
[chrome #01-1] 
[chrome #01-1] 1 spec, 0 failures
[chrome #01-1] Finished in 5.132 seconds
[chrome #01-1] 
[chrome #01-1] Executed 1 of 1 spec SUCCESS in 5 secs.

[22:10:39] I/testLogger - 

[22:10:39] I/launcher - 3 instance(s) of WebDriver still running
.[22:10:45] I/testLogger - 
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[22:10:45] I/testLogger - [chrome #01-0] PID: 11945
[chrome #01-0] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/accessibility.js
[chrome #01-0] 
[chrome #01-0] [22:10:31] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-0] Started
[chrome #01-0] Spec started
[chrome #01-0] .
[chrome #01-0]   screenreader and keyboard user accessibility features
[chrome #01-0]     ✓ should skip to the main content element
[chrome #01-0] 
[chrome #01-0] 
[chrome #01-0] 
[chrome #01-0] 
[chrome #01-0] 1 spec, 0 failures
[chrome #01-0] Finished in 11.687 seconds
[chrome #01-0] 
[chrome #01-0] Executed 1 of 1 spec SUCCESS in 12 secs.

[22:10:45] I/testLogger - 

[22:10:45] I/launcher - 3 instance(s) of WebDriver still running
..[22:12:02] I/testLogger - 
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[22:12:02] I/testLogger - [chrome #01-2] PID: 11957
[chrome #01-2] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/collections.js
[chrome #01-2] 
[chrome #01-2] [22:10:31] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-2] Started
[chrome #01-2] Spec started
[chrome #01-2] [22:11:45] W/element - more than one element found for locator By(css selector, .protractor-test-dashboard-link) - the first result will be used
[chrome #01-2] .
[chrome #01-2]   Collections
[chrome #01-2]     ✓ visits the collection editor
[chrome #01-2] .    ✓ visits the collection player
[chrome #01-2] 
[chrome #01-2] 
[chrome #01-2] 
[chrome #01-2] 
[chrome #01-2] 2 specs, 0 failures
[chrome #01-2] Finished in 87.992 seconds
[chrome #01-2] 
[chrome #01-2] Executed 2 of 2 specs SUCCESS in 1 min 28 secs.

[22:12:02] I/testLogger - 

[22:12:02] I/launcher - 3 instance(s) of WebDriver still running
F[22:13:43] I/testLogger - 
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[22:13:43] I/testLogger - [chrome #01-5] PID: 18276
[chrome #01-5] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/explorationFeedback.js
[chrome #01-5] 
[chrome #01-5] [22:12:02] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-5] Started
[chrome #01-5] Spec started
[chrome #01-5] F
[chrome #01-5]   ExplorationFeedback
[chrome #01-5]     ✗ adds feedback to an exploration
[chrome #01-5]       - Failed: Could not find exploration tile with name Sample Exploration
[chrome #01-5] 
[chrome #01-5] 
[chrome #01-5] 
[chrome #01-5] Failures:
[chrome #01-5] 1) ExplorationFeedback adds feedback to an exploration
[chrome #01-5]   Message:
[chrome #01-5]     Failed: Could not find exploration tile with name Sample Exploration
[chrome #01-5]   Stack:
[chrome #01-5]     Error: Failed: Could not find exploration tile with name Sample Exploration
[chrome #01-5]         at /home/arya/Documents/opensource/node_modules/jasminewd2/index.js:64:48
[chrome #01-5]         at ControlFlow.emit (/home/arya/Documents/opensource/node_modules/selenium-webdriver/lib/events.js:62:21)
[chrome #01-5]         at ControlFlow.shutdown_ (/home/arya/Documents/opensource/node_modules/selenium-webdriver/lib/promise.js:2565:10)
[chrome #01-5]         at shutdownTask_.MicroTask (/home/arya/Documents/opensource/node_modules/selenium-webdriver/lib/promise.js:2490:53)
[chrome #01-5] 
[chrome #01-5] 1 spec, 1 failure
[chrome #01-5] Finished in 99.88 seconds
[chrome #01-5] 
[chrome #01-5] **************************************************
[chrome #01-5] *                    Failures                    *
[chrome #01-5] **************************************************
[chrome #01-5] 
[chrome #01-5] 1) ExplorationFeedback adds feedback to an exploration
[chrome #01-5]   - Failed: Could not find exploration tile with name Sample Exploration
[chrome #01-5] 
[chrome #01-5] Executed 1 of 1 spec (1 FAILED) in 1 min 40 secs.

[22:13:43] I/testLogger - 

[22:13:43] I/launcher - 3 instance(s) of WebDriver still running
..[22:16:43] I/testLogger - 
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[22:16:43] I/testLogger - [chrome #01-6] PID: 20661
[chrome #01-6] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/explorationRating.js
[chrome #01-6] 
[chrome #01-6] [22:13:44] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-6] Started
[chrome #01-6] Spec started
[chrome #01-6] .
[chrome #01-6]   Library index page
[chrome #01-6]     ✓ should display ratings on exploration when minimum ratings have been submitted
[chrome #01-6] 
[chrome #01-6] 
[chrome #01-6] 
[chrome #01-6] 
[chrome #01-6] 1 spec, 0 failures
[chrome #01-6] Finished in 178.779 seconds
[chrome #01-6] 
[chrome #01-6] Executed 1 of 1 spec SUCCESS in 2 mins 59 secs.

[22:16:43] I/testLogger - 

[22:16:43] I/launcher - 3 instance(s) of WebDriver still running
..[22:19:48] I/testLogger - 
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[22:19:48] I/testLogger - [chrome #01-4] PID: 13191
[chrome #01-4] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/embedding.js
[chrome #01-4] 
[chrome #01-4] [22:10:46] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-4] Started
[chrome #01-4] Spec started
[chrome #01-4] .
[chrome #01-4]   Embedding
[chrome #01-4]     ✓ should display and play embedded explorations
[chrome #01-4] .    ✓ should use the exploration language as site language.
[chrome #01-4] 
[chrome #01-4] 
[chrome #01-4] 
[chrome #01-4] 
[chrome #01-4] 2 specs, 0 failures
[chrome #01-4] Finished in 540.477 seconds
[chrome #01-4] 
[chrome #01-4] Executed 2 of 2 specs SUCCESS in 9 mins.

[22:19:48] I/testLogger - 

[22:19:48] I/launcher - 3 instance(s) of WebDriver still running
.[22:20:54] I/testLogger - 
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[22:20:54] I/testLogger - [chrome #01-7] PID: 24468
[chrome #01-7] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/hintsAndSolutions.js
[chrome #01-7] 
[chrome #01-7] [22:16:44] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-7] Started
[chrome #01-7] Spec started
[chrome #01-7] .
[chrome #01-7]   HintsAndSolutions
[chrome #01-7]     ✓ uses hints and solutions in an exploration
[chrome #01-7] 
[chrome #01-7] 
[chrome #01-7] 
[chrome #01-7] 
[chrome #01-7] 1 spec, 0 failures
[chrome #01-7] Finished in 248.974 seconds
[chrome #01-7] 
[chrome #01-7] Executed 1 of 1 spec SUCCESS in 4 mins 9 secs.

[22:20:54] I/testLogger - 

[22:20:54] I/launcher - 3 instance(s) of WebDriver still running
......[22:23:24] I/testLogger - 
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[22:23:24] I/testLogger - [chrome #01-9] PID: 29301
[chrome #01-9] Specs: /home/arya/Documents/opensource/oppia/core/tests/protractor/i18n.js
[chrome #01-9] 
[chrome #01-9] [22:20:54] I/hosted - Using the selenium server at http://localhost:4444/wd/hub
[chrome #01-9] Started
[chrome #01-9] Spec started
[chrome #01-9] .
[chrome #01-9]   Site language
[chrome #01-9]     ✓ should change after selecting a different language
[chrome #01-9] [22:21:31] W/element - more than one element found for locator By(css selector, .protractor-test-system-language-selector) - the first result will be used
[chrome #01-9] .    ✓ should use language selected in the Preferences page.
[chrome #01-9] [22:22:02] W/element - more than one element found for locator By(css selector, .protractor-test-system-language-selector) - the first result will be used
[chrome #01-9] .    ✓ should save the language selected in the footer into the preferences.
[chrome #01-9] .    ✓ should be used in titles of pages without controllers
[chrome #01-9] .    ✓ should not change in an exploration
[chrome #01-9] 
[chrome #01-9] 
[chrome #01-9] 
[chrome #01-9] 
[chrome #01-9] 5 specs, 0 failures
[chrome #01-9] Finished in 148.851 seconds
[chrome #01-9] 
[chrome #01-9] Executed 5 of 5 specs SUCCESS in 2 mins 29 secs.

[22:23:24] I/testLogger - 

[22:23:24] I/launcher - 3 instance(s) of WebDriver still running::