github-starred/ollama
2
0
Fork 0
mirror of https://github.com/ollama/ollama.git synced 2026-05-06 16:11:34 -05:00
Code Issues 14.5k Packages Projects Releases 120 Wiki Activity

[GH-ISSUE #2568] /set system in CLI still append to System Prompt after ollama#2542 #1507

New Issue
Closed
opened 2026-04-12 11:25:10 -05:00 by GiteaMirror · 1 comment
GiteaMirror commented 2026-04-12 11:25:10 -05:00
Owner
Copy Link

Originally created by @hyjwei on GitHub (Feb 17, 2024).
Original GitHub issue: https://github.com/ollama/ollama/issues/2568

Originally assigned to: @pdevine on GitHub.

This is a follow-up for #2492 . Thanks for fixing that issue. However, /set system in CLI still append to System Prompt after PR ollama#2542 .

In the second scenario of #2492, when I load a model, then use /set system to specify a custom System Prompt, it does replace the old one.

However, if I load a model, start a chat with the old System Prompt at first, then use /set system to specify a custom System Prompt, it will append to the old one instead of replacing that.

How to replicate

Start a new server by ollama serve with OLLAMA_DEBUG=1
Run client with any model, for example, ollama run phi
Start a chat (for example, user prompt hello), and you can find the prompt debug info on server side looks like (and this is expected):

time=2024-02-17T16:34:41.346-05:00 level=DEBUG source=routes.go:1165 msg="chat handler" prompt="System: A chat between a curious user and an artificial intelligence assistant. The assistant gives helpful answers to the user's questions.\nUser: hello\nAssistant:"

Then, set system prompt by /set system

/set system I want you to speak French only.

And input user prompt hello again, and you can find prompt debug info:

time=2024-02-17T16:35:05.369-05:00 level=DEBUG source=routes.go:1165 msg="chat handler" prompt="System: A chat between a curious user and an artificial intelligence assistant. The assistant gives helpful answers to the user's questions.\nUser: hello\nAssistant: Hello! How can I assist you today?\nSystem: I want you to speak French only.\nUser: hello\nAssistant:"

This time, you can find that the new System Prompt is appended to the chat, which includes the old System Prompt and User/Assistant conversation.
From this point, the new system prompt by /set system will also append to the old prompts, even if I don't give any new user prompt. Thus multiple /set system (no user prompt in between) will make prompt look like:

time=2024-02-17T16:42:31.942-05:00 level=DEBUG source=routes.go:1165 msg="chat handler" prompt="System: A chat between a curious user and an artificial intelligence assistant. The assistant gives helpful answers to the user's questions.\nUser: hello\nAssistant: Hello! How can I assist you today?\nSystem: I want you to speak French only.\nUser: hello\nAssistant: Bonjour! Je parle français. Comment ça va? (Hello! I speak French. How are you?)\nSystem: I want you to speak English only.\nUser: hello\nAssistant: Hello! How can I assist you today?\nSystem: I want you to speak German only.\nUser: \nAssistant:System: I want you to speak Italian only.\nUser: hello\nAssistant:"

You can see that the User Prompt and model response is empty between the last two System Prompts.

My thought on this issue

I am not sure if changing system prompt after user prompt is a valid scenario or not, nor what behavior can be right. But I do believe that at least, if I give /set system twice or more without user prompt, only the last one should take effect.

Originally created by @hyjwei on GitHub (Feb 17, 2024). Original GitHub issue: https://github.com/ollama/ollama/issues/2568 Originally assigned to: @pdevine on GitHub. This is a follow-up for #2492 . Thanks for fixing that issue. However, `/set system` in CLI still append to System Prompt after PR ollama#2542 . In the second scenario of #2492, when I load a model, then use `/set system` to specify a custom System Prompt, it does replace the old one. However, if I load a model, start a chat with the old System Prompt at first, then use `/set system` to specify a custom System Prompt, it will append to the old one instead of replacing that. ### How to replicate Start a new server by `ollama serve` with `OLLAMA_DEBUG=1` Run client with any model, for example, `ollama run phi` Start a chat (for example, user prompt `hello`), and you can find the prompt debug info on server side looks like (and this is expected): ``` time=2024-02-17T16:34:41.346-05:00 level=DEBUG source=routes.go:1165 msg="chat handler" prompt="System: A chat between a curious user and an artificial intelligence assistant. The assistant gives helpful answers to the user's questions.\nUser: hello\nAssistant:" ``` Then, set system prompt by `/set system` ``` /set system I want you to speak French only. ``` And input user prompt `hello` again, and you can find prompt debug info: ``` time=2024-02-17T16:35:05.369-05:00 level=DEBUG source=routes.go:1165 msg="chat handler" prompt="System: A chat between a curious user and an artificial intelligence assistant. The assistant gives helpful answers to the user's questions.\nUser: hello\nAssistant: Hello! How can I assist you today?\nSystem: I want you to speak French only.\nUser: hello\nAssistant:" ``` This time, you can find that the new System Prompt is appended to the chat, which includes the old System Prompt and User/Assistant conversation. From this point, the new system prompt by `/set system` will also append to the old prompts, even if I don't give any new user prompt. Thus multiple `/set system` (no user prompt in between) will make prompt look like: ``` time=2024-02-17T16:42:31.942-05:00 level=DEBUG source=routes.go:1165 msg="chat handler" prompt="System: A chat between a curious user and an artificial intelligence assistant. The assistant gives helpful answers to the user's questions.\nUser: hello\nAssistant: Hello! How can I assist you today?\nSystem: I want you to speak French only.\nUser: hello\nAssistant: Bonjour! Je parle français. Comment ça va? (Hello! I speak French. How are you?)\nSystem: I want you to speak English only.\nUser: hello\nAssistant: Hello! How can I assist you today?\nSystem: I want you to speak German only.\nUser: \nAssistant:System: I want you to speak Italian only.\nUser: hello\nAssistant:" ``` You can see that the User Prompt and model response is empty between the last two System Prompts. ## My thought on this issue I am not sure if changing system prompt after user prompt is a valid scenario or not, nor what behavior can be right. But I do believe that at least, if I give `/set system` twice or more without user prompt, only the last one should take effect.
GiteaMirror added the bug label 2026-04-12 11:25:10 -05:00
GiteaMirror commented 2026-04-12 11:25:11 -05:00
Author
Owner
Copy Link

@pdevine commented on GitHub (Dec 20, 2024):

This has been working for a while, but the issue got lost. Going to go ahead and close it.

<!-- gh-comment-id:2557889932 --> @pdevine commented on GitHub (Dec 20, 2024): This has been working for a while, but the issue got lost. Going to go ahead and close it.
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
amd
api
app
bug
build
cli
cloud
compatibility
context-length
create
docker
documentation
embeddings
feature request
feedback wanted
good first issue
gpt-oss
gpu
harmony
help wanted
image
install
intel
js
launch
linux
macos
memory
mlx
model
needs more info
networking
nvidia
ollama.com
performance
pull-request
Mirrored from GitHub Pull Request
 python
question
registry
rendering
thinking
tools
top
vulkan
windows
wsl
No Label bug
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
GiteaMirror ninjasurge
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: github-starred/ollama#1507
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?