: GitBench
Detached HEAD state - identify the detached HEAD commit
Tests ability to identify a detached HEAD commit using reflog. Evaluates detached-HEAD diagnosis and recovery.

These commands set up the repo before the model sees the prompt. They define the starting file structure, staged changes, and Git history.

  1. 01 git init
  2. 02 git config user.email 'test@test.com'
  3. 03 git config user.name 'Test User'
  4. 04 echo 'line1' > data.txt
  5. 05 git add data.txt
  6. 06 git commit -m 'First commit'
  7. 07 echo 'line2' >> data.txt
  8. 08 git add data.txt
  9. 09 git commit -m 'Second commit'
  10. 10 echo 'line3' >> data.txt
  11. 11 git add data.txt
  12. 12 git commit -m 'Third commit - WIP experimental'
  13. 13 git checkout HEAD~1
Prompt
You are in detached HEAD state at HEAD~1. You made some experimental changes and committed them in a detached HEAD state. The commit 'Third commit - WIP experimental' was made on a detached HEAD. Use git reflog to find the commit hash of that experimental commit so you can return to it.
Expected
Third commit - WIP experimental
Loading campaign evidence…
deepseek/deepseek-v4-flash:high PASS 100% 217 in → 1,887 out (1,954 reasoning)
The commit hash for the experimental commit "Third commit - WIP experimental" is **fd2b9f116bb054eaaf9e31ea408b420d1e60e89f**. You can return to it using: ```bash git checkout fd2b9f116bb054eaaf9e31ea408b420d1e60e89f ```
deepseek/deepseek-v4-flash:none PASS 100% 227 in → 201 out (0 reasoning)
Based on the Git reflog you provided, the commit hash for the experimental commit made in detached HEAD state is: **`b7fbdbbf4afab41ad3d974f92e58261bfaed9f0e`** This is the commit labeled `HEAD@{1}: commit: Third commit - WIP experimental`. To return to this commit, you can use either of these commands: ```bash git checkout b7fbdbbf4afab41ad3d974f92e58261bfaed9f0e ``` Or if you want to create a branch at this point to preserve your work: ```bash git checkout -b experimental-branch b7fbdbbf4afab41ad3d974f92e58261bfaed9f0e ``` The second option is generally recommended because it creates a named branch, making it easier to track and manage your experimental changes going forward.
deepseek/deepseek-v4-flash:none__json_schema PASS 100% 216 in → 28 out (0 reasoning)
c52eeb11d25dff337b2590101740b4fb05170669
JSON Schema Structured Output
(raw) {"ref": "c52eeb11d25dff337b2590101740b4fb05170669"}
mistralai/devstral-2512 PASS 100% 260 in → 182 out
Based on the `git reflog` output, the commit hash for the experimental commit "Third commit - WIP experimental" is: ``` 6abbb4ea339fa88f381e083b797b627ef5a0567e ``` You can return to this commit by running: ```bash git checkout 6abbb4ea339fa88f381e083b797b627ef5a0567e ``` Or if you want to create a new branch at this commit to preserve it: ```bash git checkout -b experimental-branch 6abbb4ea339fa88f381e083b797b627ef5a0567e ```
mistralai/devstral-2512__json_schema PASS 100% 267 in → 42 out
ad48f366f707ba74b269265a402412eb352607ca
JSON Schema Structured Output
(raw) {"ref": "ad48f366f707ba74b269265a402412eb352607ca"}
nvidia/nemotron-3-nano-30b-a3b:high PASS 100% 275 in → 362 out (127 reasoning)
The commit you're looking for is recorded in the reflog entry **HEAD@{1}** with the message: ``` Third commit - WIP experimental ``` Its SHA‑1 hash is: ``` 9f3ef49ce2f3ee57c3ba97e74e905e970003e68f ``` You can return to that exact commit by checking it out: ```bash git checkout 9f3ef49ce2f3ee57c3ba97e74e905e970003e68f ``` *(You can also use the short prefix `9f3ef49c` if Git can disambiguate it, or just type the first 7 characters `9f3ef49`.)*
nvidia/nemotron-3-nano-30b-a3b:high__json_schema PASS 100% 279 in → 220 out (139 reasoning)
f5e0d7250ad4659342ac3aac0bc76f5d9b8d2474
JSON Schema Structured Output
(raw) { "ref": "f5e0d7250ad4659342ac3aac0bc76f5d9b8d2474" }
nvidia/nemotron-3-nano-30b-a3b:none PASS 100% 262 in → 429 out (0 reasoning)
The commit hash for the experimental commit **"Third commit - WIP experimental"** is explicitly listed in the `git reflog` output: ``` ab7a4efa47523f5e500cb5f18305adb12d8cdb81 HEAD@{1}: commit: Third commit - WIP experimental ``` ### Why? - Git reflog shows the history of HEAD changes. The `HEAD@{N}` notation refers to the state of HEAD at a specific point in time. - `HEAD@{1}` (the most recent reference before the current state) corresponds to the commit message **"Third commit - WIP experimental"**. - The hash `ab7a4efa47523f5e500cb5f18305adb12d8cdb81` is the unique identifier for that commit. ### How to return to it? To move back to this specific commit: ```bash git checkout ab7a4efa47523f5e500cb5f18305adb12d8cdb81 ``` ### Key Takeaway: - The reflog entry `HEAD@{1}` directly points to the commit hash you need (`ab7a4efa47523f5e500cb5f18305adb12d8cdb81`). - You don’t need to parse or derive it—this hash is explicitly provided in the reflog. > 💡 **Note**: If you run `git checkout ab7a4efa47523f5e500cb5f18305adb12d8cdb81`, you’ll be back at the detached HEAD state of that commit. To make it a named branch later, create a branch first (e.g., `git checkout -b temp ab7a...`), then switch to it. But for now, just use the hash to return to the commit.
poolside/laguna-xs.2:high PASS 100% 295 in → 356 out (176 reasoning)
Based on the git reflog you provided, I can see the commit hash for your experimental commit. The commit **"Third commit - WIP experimental"** has the hash: **`a87495c543232eb68516ae8b0ee1ef57d600bab5`** You can see this at `HEAD@{1}` in your reflog output. To return to this experimental commit, you can run: ```bash git checkout a87495c543232eb68516ae8b0ee1ef57d600bab5 ``` Or simply use the reflog reference: ```bash git checkout HEAD@{1} ``` This will put you back at that experimental commit where you made your WIP changes.
poolside/laguna-xs.2:high__json_schema PASS 100% 300 in → 350 out (309 reasoning)
3f8fbe38a81bc83da7fc7f4ce7f09e47797ff422
JSON Schema Structured Output
(raw) {"ref": "3f8fbe38a81bc83da7fc7f4ce7f09e47797ff422"}
poolside/laguna-xs.2:none PASS 100% 303 in → 184 out (0 reasoning)
I can see from the git reflog that you're looking for the commit "Third commit - WIP experimental" which was made in a detached HEAD state. Looking at the reflog output, the commit hash you need is **1c12f8993e01aebd97a72bf04f895dd778820247**. This corresponds to: - `HEAD@{1}: commit: Third commit - WIP experimental` To return to this experimental commit, you can use: ```bash git checkout 1c12f8993e01aebd97a72bf04f895dd778820247 ``` This will put you back in detached HEAD state at your experimental commit, allowing you to continue working with those changes.
poolside/laguna-xs.2:none__json_schema PASS 100% 308 in → 41 out (0 reasoning)
ead70ee3f70354be3a3c74c15a331a90f4e9ee65
JSON Schema Structured Output
(raw) {"ref": "ead70ee3f70354be3a3c74c15a331a90f4e9ee65"}
Invalid JSON. Output: Thecommit hash for `Third commit - WIP experimental` is **fe4ccd891a816a1c3f4d54cd5efbe4f231c89357**. To return to it, run: ```bash git checkout fe4ccd891a816a1c3f4d54cd5efbe4f231c89357 ``` or (with newer Git): ```bash git switch --detach fe4ccd891a816a1c3f4d54cd5efbe4f231c89357 ```
JSON Schema Structured Output
Structured Output Error
Failed to parse structured JSON response: Expecting value: line 1 column 1 (char 0)
Failure: Failed to parse structured JSON response: Expecting value: line 1 column 1 (char 0)
nvidia/nemotron-3-nano-30b-a3b:none__json_schema FAIL 0% 277 in → 22 out (0 reasoning)
REF-DETACHED-HEAD-AT-HEAD~1
JSON Schema Structured Output
(raw) { "ref": "REF-DETACHED-HEAD-AT-HEAD~1" }
Failure: Expected output to mention target hash prefix/full hash or matching HEAD@{n} selector for 'Third commit - WIP experimental'