Bumping the version of an existing project

Increasing the version of an already existing project is often times a cumbersome and error prone process, since the version has to be changed in multiple places. To facilitate this process, mlf-core provides a bump-version command, which conveniently increases the version across several files. Additionally, bump-version inserts a new section into the changelog using the specified new version.

New Version (Date)





bump-version will verify that your new version adheres to semantic versioning and that you are not trying to update it unreasonably. It is for example not allowed to bump from 2.0.0 to 7.1.2, since in a normal development workflow only 2.0.1, 2.1.0 or 3.0.0 adhere to consecutive semantic versioning. Note that SNAPSHOT versions are allowed! However, it must still follow semantic versioning. Version 1.2.5 therefore cannot be the predecessor of 1.2.5-SNAPSHOT, but only 1.2.4.


The bump-version command follows the syntax

$ mlf-core bump-version <OPTIONS> X.X.X <PATH>
  • X.X.X : The new version, where the X correspond to integers adhering to consecutive semantic versioning. You may append -SNAPSHOT.

  • PATH [CWD]: The path to the mlf_core.cfg file, which contains all locations, where the version should be increased.


  • --downgrade : To downgrade a version.

    The changelog won’t be modified. Only use this option as a last resort if something went horribly wrong in your development process. In a normal development workflow, this should never be necessary.

  • --project-version : To get the current project version.

    No version bumping will be triggered. Using this flag will cancel any commands executed after and exits the program.


All templates of mlf-core ship with a mlf-core.cfg file, which defines all files bump-version examines.

The bump-version configuration begins with the section:

current_version = 0.1.0

where the current version is defined. All files are either white- or blacklisted (see below for explanations). An arbitrary name is followed by the path to the file: arbitrary_name = path_to_file.

Whitelisted files are listed below a [bumpversion_files_whitelisted] section, e.g.:

dot_mlf-core = .mlf-core.yml
conf_py = docs/conf.py

All files, which are whitelisted are searched for patterns matching X.X.X, which are updated to the specified new versions. Any lines, which contain the string <<mlf-core_NO_BUMP>> will be ignored.

If files, like Maven pom.xml files, contain many version patterns matching X.X.X, it may be a better idea to blacklist them (section [bumpversion_files_blacklisted]) and enable only specific lines to be updated:

pom = pom.xml

Analogously to whitelisted files, which allow for specific lines to be ignored, blacklisted files allow for specific lines to be forcibly updated using the string <<mlf-core_FORCE_BUMP>>.

Note that those tags must be on the same line as the version (commonly placed in a comment), otherwise they wont work!