Found in discussion: https://github.com/Particular/GitVersion/issues/201 Question: what does "0.2.0-unstable.10+10" mean? It's the result of SetBuildVersion call. When I debug with this url: /url https://github.com/Orcomp/C5Intervals /b develop /output buildserver Caused by a call to semanticVersion.ToString("f") According to @JakeGinnivan , it might be a bug.