A branch named push will break antora
https://gitlab.com/antora/antora/blob/master/packages/content-aggregator/lib/aggregate-content.js#L237 uses the "in" operator on an array object. However if the name of a branch happens to collide with the name of a method on the javascript object then antora will add that branch to be processed.
I am not a JS dev, but I believe the if statement should be
if (accum.indexOf(name) >= 0) {
Edited by Summers Pittman