Presuming the OP means some sort of "Continuous Integration" system like Jenkins. Jenkins will let you define tasks to be run (such as building a package and/or then running its test suite) "continuously" whenever changes are committed to source control (so that you know fairly quickly if someone's commit broke the build). To do this you usually have some sort of agent process running on a pool of worker machines which runs the task (some sort of shell script, although Jenkins has Java roots so something like ant or maven would also be common). That worker may be running as a different user context (so there's possibly environment or shell issues) or possibly shell / tty related issues.