1. A method for data management, the method comprising: identifying, by one or more processors, a source closure, a target file set, and a previously merged closure, wherein the source closure is a closure of files that includes changed files to merge into the target file set, and wherein the previously merged closure is a closure of files previously merged into the target file set; loading, by one or more processors, the identified source closure, the previously merged closure, and a closure of ancestor files shared by the identified source closure and the previously merged closure into a merge session; and determining, by one or more processors, one or more file merge conflicts in the merge session based on differences between a comparison of the identified source closure to the closure of ancestor files and a comparison of the previously merged closure to the closure of ancestor files, wherein the one or more file merge conflicts include a file that is present in the closure of ancestor files but is not present in either the identified source closure or the previously merged closure.