Command not found in Execute Shell build step

[morty]

I have installed Jenkins on Ubuntu 15.10. In a Jenkins job I have a single Execute Shell step with:

virtualenv --no-site-packages virtual_django
cd virtual_django/bin
pwd
dir
source activate

When I run the job I get:

+ 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 in the Jenkins job the source command is not found. It works fine from a terminal where I have logged in as the jenkins user. 

Why can't the above script find the source command when run inside the Jenkins job?

[thomas....@teamaol.com]

Have you tried this? => http://stackoverflow.com/questions/670191/getting-a-source-not-found-error-when-using-source-in-a-bash-script
Put it as first line .... "#!/bin/bash"

[morty]

Thanks that fixed the problem.