If you’re pulling from trunk, then you’re pulling from something that doesn’t have a base version.
1.4, 1.6.x, and 1.8 are all branches from trunk that occurred at one point in time. 1.8 has already been branched and is set to become the next major release. After that occurs, we will continue development inside of trunk, and then one day branch off of trunk in preparation for the next major release.