Cannot activate python virtual env in jenkins shell script

Question

I have installed Jenkins on ubuntu 15.10. In a shell build step I am trying to create a Python virtual environment and activate it:

But I get the following error when I run the job:

/tmp/hudson4515625893361069094.sh: 9: /tmp/hudson4515625893361069094.sh: source: not found

More from the log:

[django-demo] $ /bin/sh -xe /tmp/hudson4515625893361069094.sh
+ virtualenv --no-site-packages virtual_django
New python executable in virtual_django/bin/python2
Also creating executable in virtual_django/bin/python
Installing setuptools, pip...done.
Running virtualenv with interpreter /usr/bin/python2
+ cd virtual_django/bin
+ pwd
/var/lib/jenkins/workspace/django-demo/virtual_django/bin
+ dir
activate      activate.fish easy_install      pip   pip2.7  python2
activate.csh  activate_this.py  easy_install-2.7  pip2  python  python2.7
+ source activate
/tmp/hudson4515625893361069094.sh: 9: /tmp/hudson4515625893361069094.sh: source: not found
Build step 'Execute shell' marked build as failure

So the virtual environment was created successfully but it cannot be activated because the source command cannot be found.

I did verify that I can indeed run the source activate command from a terminal on the machine as the jenkins user in the corresponding workspace:

jenkins@vmi63860 ~/workspace/django-demo/virtual_django/bin ((HEAD detached at 290c6a4)) $ source activate
(virtual_django)jenkins@vmi63860 ~/workspace/django-demo/virtual_django/bin ((HEAD detached at 290c6a4)) $ exit

So why does it fail when I run it under the Jenkins job?

Solution

Found a similar post here:

https://stackoverflow.com/questions/670191/getting-a-source-not-found-error-when-using-source-in-a-bash-script

The solution is to add:

#!/bin/bash

in the first line of the script step: