title: How to fix 'script returned exit code 1' when running Jenkins pipeline
body: <p>I am defining a pipeline using Jenkins Blue Ocean.</p>
  
  <p>I'm trying to do a simple python pep8 coding convention, but if I go inside the shell and type the command directly, it runs fine.</p>
  
  <p>But when the same command is executed in the pipeline, it is executed, but at the end
  'script returned exit code 1' is displayed.
  Because of this error code, it does not go to the next step.</p>
  
  <p>Is there a workaround?</p>
  
  <pre><code>using credential github
   &gt; git rev-parse --is-inside-work-tree # timeout=10
  Fetching changes from the remote Git repository
   &gt; git config remote.origin.url https://github.com/YunTaeIl/jenkins_retest.git # timeout=10
  Cleaning workspace
   &gt; git rev-parse --verify HEAD # timeout=10
  Resetting working tree
   &gt; git reset --hard # timeout=10
   &gt; git clean -fdx # timeout=10
  Fetching without tags
  Fetching upstream changes from https://github.com/YunTaeIl/jenkins_retest.git
   &gt; git --version # timeout=10
  using GIT_ASKPASS to set credentials GitHub Access Token
   &gt; git fetch --no-tags --progress -- https://github.com/YunTaeIl/jenkins_retest.git +refs/heads/master:refs/remotes/origin/master # timeout=10
  Checking out Revision fe49ddf379732305a7a50f014ab4b25f9382c913 (master)
   &gt; git config core.sparsecheckout # timeout=10
   &gt; git checkout -f fe49ddf379732305a7a50f014ab4b25f9382c913 # timeout=10
   &gt; git branch -a -v --no-abbrev # timeout=10
   &gt; git branch -D master # timeout=10
   &gt; git checkout -b master fe49ddf379732305a7a50f014ab4b25f9382c913 # timeout=10
  Commit message: "Added Jenkinsfile"
   &gt; git rev-list --no-walk bc12a035337857b29a4399f05d1d4442a2f0d04f # timeout=10
  Cleaning workspace
   &gt; git rev-parse --verify HEAD # timeout=10
  Resetting working tree
   &gt; git reset --hard # timeout=10
   &gt; git clean -fdx # timeout=10
  + ls
  Jenkinsfile
  README.md
  jenkins-retest
  + python3.7 --version
  Python 3.7.3
  + python3.7 -m flake8 jenkins-retest
  jenkins-retest/N801_py3.py:3:1: E302 expected 2 blank lines, found 0
  jenkins-retest/N801_py3.py:6:1: E302 expected 2 blank lines, found 0
  jenkins-retest/N801_py3.py:9:1: E302 expected 2 blank lines, found 0
  jenkins-retest/N801_py3.py:12:1: E302 expected 2 blank lines, found 0
  jenkins-retest/N801_py3.py:15:1: E302 expected 2 blank lines, found 0
  jenkins-retest/N801_py3.py:18:1: E302 expected 2 blank lines, found 0
  jenkins-retest/N801_py3.py:24:1: E303 too many blank lines (4)
  jenkins-retest/N801_py3.py:24:11: E999 SyntaxError: invalid syntax
  jenkins-retest/python_testfile.py:1:1: E999 SyntaxError: invalid syntax
  jenkins-retest/python_testfile.py:1:2: E228 missing whitespace around modulo operator
  jenkins-retest/python_testfile.py:3:1: E402 module level import not at top of file
  jenkins-retest/python_testfile.py:3:20: W291 trailing whitespace
  jenkins-retest/python_testfile.py:5:1: E302 expected 2 blank lines, found 1
  jenkins-retest/python_testfile.py:8:1: E305 expected 2 blank lines after class or function definition, found 0
  jenkins-retest/python_testfile.py:11:33: W291 trailing whitespace
  jenkins-retest/python_testfile.py:12:1: E402 module level import not at top of file
  jenkins-retest/python_testfile.py:12:19: W291 trailing whitespace
  jenkins-retest/python_testfile.py:14:4: E714 test for object identity should be 'is not'
  jenkins-retest/python_testfile.py:17:16: W291 trailing whitespace
  jenkins-retest/python_testfile.py:18:80: E501 line too long (95 &gt; 79 characters)
  script returned exit code 1
  </code></pre>