This is only true if you assume that the rewrite branch will be broken the entire time. You're only blocking the team if your work will be unusable until it's

This is only true if you assume that the rewrite branch will be broken the entire time. You're only blocking the team if your work will be unusable until it's done. If that's the case, then you're also assuming at some point in the future you'll complete the work, get everything working again, and then merge everything back to master. It won't likely play out that way, though. More likely is that: * Your child branch will be test-broken and likely build-broken almost the entire time you develop. * You'll stop taking frequent merges as they become painful because you're clearly not doing the work to patch everything up (and can't, because you've broken everything and likely can't even run tests). * You'll be "almost done" and then spend three weeks trying to get everything building and testing again. * You'll tell everyone to freeze checkins because you need to get merged and it's impossible because the branch is so far out of sync and and you're now conflicting on every tiny change. * You'll finally push your merge back with half the tests disabled. * The entire team will spend another month cleaning up the mess. I've never seen a big feature/rewrite branch play out any other way.