Q&A forums are today a valuable tool to assist developers in programming tasks. Unfortunately, contributions to these forums are often unclear and incomplete. Docker is a container solution that enables software developers to encapsulate an operating environment and could help address reproducibility issues. This artile reports on a feasibility study to evaluate if Docker can help improve reproducibility in Stack Overflow. We started surveying Stack Overflow users to understand their perceptions on the proposal of using Docker to reproduce Stack Overflow posts. Participants were critical and mentioned two important aspects: cost and need. To validate their criticism, we conducted an exploratory study focused on understanding how costly the task of creating containers for posts is for developers. Overall, results indicate that the cost of creating containers is not high, especially due to the fact that dockerfiles are highly similar and small. Based on these findings we developed a tool, dubbedFrisk, to assist developers in creating containers for those posts. We then conducted a user study to evaluate interest of Stack Overflow developers on the tool. We found that, on average, users spent nearly ten minutes interacting withFriskand that 45.3% of the 563Frisksessions we created for existing posts resulted in a successful access to the corresponding web service by the owners of the post. Overall, this artile provides early evidence that the use of Docker in Q&A forums should be encouraged for configuration-related posts.

Dealing with high testing costs remains an important problem in Software Engineering. Test suite parallelization is an important approach to address this problem. This paper reports our findings on the usage and impact of test suite parallelization in open-source projects. It provides recommendations to practitioners and tool developers to speed up test execution. Considering a set of 468 popular Java projects we analyzed, we found that 24% of the projects contain costly test suites but parallelization features still seem underutilized in practice - only 19.1% of costly projects use parallelization. The main reported reason for adoption resistance was the concern to deal with concurrency issues. Results suggest that, on average, developers prefer high predictability than high performance in running tests.