[skydhash]

> I've had to deep regression analysis and archeology to make sure that regressions aren't recurring or stop recurring, because regressions can recur. An engineer that […] looking at the exact commit where it was made than the PR it was made in.

That mostly a staple of the merge workflows where people are crisscrossing merges all over the place. At the end you have those horrendous diffs.

A rebase (and squash) only considers the tip of the main branch (which is a working state) and add changes that bring it to the next working state. You’re always aware of the latest working model of the code because that’s the starting point of your work (not something from $days ago). There’s no bad merges in the history of the PR branch.

[WorldMaker]

I've seen some really bad trainwreck merges in rebase heavy workflows, too. (Unwinding them is awful.) Rebases create just as many merge conflicts as merge commits do [0], but rebases don't save the evidence for them. Just because the evidence was lost of them doesn't mean the merge conflict markers were never there.

Any time you integrate two branches, no matter how long running or short running, you have possible merge conflicts. Like I said, I prefer keeping that integration log as a tangible source control artifact. I understand how many people don't care for it. But don't mistake it for solely an aesthetic choice. Merge conflicts are a necessary part of source control and sweeping them under the rug is one way with dealing with them, but in my opinion not exactly the healthiest way.

[0] ETA: Merge conflicts are not just a technical issue, but a communications and coordination issue. Software development is a social activity and as long as it is a social activity it creates merge conflicts.

[skydhash]

I do agree that merge conflicts are a signal of a deeper collaboration issue.

> Merge conflicts are a necessary part of source control and sweeping them under the rug is one way with dealing with them, but in my opinion not exactly the healthiest way.

I don’t agree that retaining them is necessary. Merge workflows encourage long running branches. Sometimes divergence in understanding does not create conflicts and that’s how regression happens.

With most rebase workflow, the commit list is often kept short (which is why squashing them is often correct). Most of mine have been below five. Such patch is easy to review and reason according to the latest knowledge of the code. Also easier to cherrypick and apply to an old version of the code.

[WorldMaker]

Use merge commits does not mean using "merge workflows with long running branches".

"Merge early and often" is just as useful of a concept as "rebase often". The workflow is often exactly the same. The only real difference is extra commits to mark the merge points, and the extra commits are mostly just a UI issue when code reviewing.

A good PR UI (and GitHub isn't always, but it tries) doesn't show commits brought in from the base branch. (I think GitHub would have a simpler thing if it defaulted to a simpler `--first-parent` approach (rather than trying to math from the base branch) with an option to drill down, but I'm not a a GitHub UX designer.

Don't confuse the workflow with the DAG shape, that is more aesthetic than not.