Regex matching branches to build. The syntax of the regular expressions accepted is the syntax accepted by RE2 and described at https://github.com/google/re2/wiki/Syntax
Directory, relative to the source root, in which to run the build. This must be a relative path. If a step's dir is specified and is an absolute path, this value is ignored for that step's execution. eg. helloworld (no leading slash allowed)
Regex matching tags to build. The syntax of the regular expressions accepted is the syntax accepted by RE2 and described at https://github.com/google/re2/wiki/Syntax