add failing transcript

Author: mitchellwrosen

unison-src/transcripts/fix-5326.md

@@ -0,0 +1,125 @@
+```ucm
+scratch/main> builtins.merge lib.builtin
+```
+
+```unison
+x = 1
+```
+
+```ucm
+scratch/main> update
+scratch/main> branch foo
+scratch/main>
+```
+
+```
+main, foo
+|
+A
+```
+
+```unison
+x = 2
+```
+
+```ucm
+scratch/main> update
+scratch/main> branch bar
+scratch/main>
+```
+
+```
+main, bar
+|
+|   foo
+|   |
+B - A
+```
+
+```unison
+x = 3
+```
+
+```ucm
+scratch/main> update
+```
+
+```
+main
+|
+|   bar foo
+|   |   |
+C - B - A
+```
+
+```unison
+x = 4
+```
+
+```ucm
+scratch/main> update
+scratch/foo>
+```
+
+```
+main
+|
+|       bar foo
+|       |   |
+D - C - B - A
+```
+
+```unison
+y = 5
+```
+
+```ucm
+scratch/foo> update
+```
+
+```
+main
+|
+|       bar
+|       |
+D - C - B - A
+           /
+          E
+          |
+          foo
+```
+
+```ucm
+scratch/main> merge /foo
+```
+
+```
+main
+|
+|           bar
+|           |
+F - D - C - B - A
+ \             /
+  ----------- E
+              |
+              foo
+```
+
+```ucm:error
+scratch/main> merge /bar
+```
+
+This should be a fast-forward, but we get this shape instead (which fails due to conflicts), because we incorrectly
+compute `LCA(main, bar)` as `A`, not `B`.
+
+```
+main
+|
+|  ------------ bar
+| /            \|
+G - F - D - C - B - A
+     \             /
+      ----------- E
+                  |
+                  foo
+```

unison-src/transcripts/fix-5326.output.md

@@ -0,0 +1,259 @@
+``` ucm
+scratch/main> builtins.merge lib.builtin
+
+  Done.
+
+```
+``` unison
+x = 1
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These new definitions are ok to `add`:
+    
+      x : Nat
+
+```
+``` ucm
+scratch/main> update
+
+  Okay, I'm searching the branch for code that needs to be
+  updated...
+
+  Done.
+
+scratch/main> branch foo
+
+  Done. I've created the foo branch based off of main.
+  
+  Tip: To merge your work back into the main branch, first
+       `switch /main` then `merge /foo`.
+
+```
+``` 
+main, foo
+|
+A
+```
+
+``` unison
+x = 2
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These names already exist. You can `update` them to your
+      new definition:
+    
+      x : Nat
+
+```
+``` ucm
+scratch/main> update
+
+  Okay, I'm searching the branch for code that needs to be
+  updated...
+
+  Done.
+
+scratch/main> branch bar
+
+  Done. I've created the bar branch based off of main.
+  
+  Tip: To merge your work back into the main branch, first
+       `switch /main` then `merge /bar`.
+
+```
+``` 
+main, bar
+|
+|   foo
+|   |
+B - A
+```
+
+``` unison
+x = 3
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These names already exist. You can `update` them to your
+      new definition:
+    
+      x : Nat
+
+```
+``` ucm
+scratch/main> update
+
+  Okay, I'm searching the branch for code that needs to be
+  updated...
+
+  Done.
+
+```
+``` 
+main
+|
+|   bar foo
+|   |   |
+C - B - A
+```
+
+``` unison
+x = 4
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These names already exist. You can `update` them to your
+      new definition:
+    
+      x : Nat
+
+```
+``` ucm
+scratch/main> update
+
+  Okay, I'm searching the branch for code that needs to be
+  updated...
+
+  Done.
+
+```
+``` 
+main
+|
+|       bar foo
+|       |   |
+D - C - B - A
+```
+
+``` unison
+y = 5
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These new definitions are ok to `add`:
+    
+      y : Nat
+
+```
+``` ucm
+scratch/foo> update
+
+  Okay, I'm searching the branch for code that needs to be
+  updated...
+
+  Done.
+
+```
+``` 
+main
+|
+|       bar
+|       |
+D - C - B - A
+           /
+          E
+          |
+          foo
+```
+
+``` ucm
+scratch/main> merge /foo
+
+  I merged scratch/foo into scratch/main.
+
+```
+``` 
+main
+|
+|           bar
+|           |
+F - D - C - B - A
+ \             /
+  ----------- E
+              |
+              foo
+```
+
+``` ucm
+scratch/main> merge /bar
+
+  I couldn't automatically merge scratch/bar into scratch/main.
+  However, I've added the definitions that need attention to the
+  top of scratch.u.
+  
+  When you're done, you can run
+  
+    merge.commit
+  
+  to merge your changes back into main and delete the temporary
+  branch. Or, if you decide to cancel the merge instead, you can
+  run
+  
+    delete.branch /merge-bar-into-main
+  
+  to delete the temporary branch and switch back to main.
+
+```
+``` unison:added-by-ucm scratch.u
+-- scratch/main
+x : Nat
+x = 4
+
+-- scratch/bar
+x : Nat
+x = 2
+
+```
+
+This should be a fast-forward, but we get this shape instead (which fails due to conflicts), because we incorrectly
+compute `LCA(main, bar)` as `A`, not `B`.
+
+``` 
+main
+|
+|  ------------ bar
+| /            \|
+G - F - D - C - B - A
+     \             /
+      ----------- E
+                  |
+                  foo
+```
+