Yes, I am on the latest version
Yes, this isn’t a duplicate
Other
Update the toolkit?
“Failed to update” constantly shows in VS Code
Windows 11
None, “show output” gives nothing useful
Windows 11
4.6.0
N/A
26.4.0
N/A
Hi @ceri_waters – Can you provide the details from Show Output?
@NickWesselman It shows a big fat nothing
How often is this error displaying? Is it random, on startup, or when opening specific interfaces?
Can you try this?
Open your Command Palette by pressing Ctrl+Shift+P (Windows/Linux) or Cmd+Shift+P (macOS).
Type and select Developer: Open Logs Folder
This will launch your system’s file manager (File Explorer or Finder) directly inside the folder where VS Code stores its active text logs.
Grab that folder path and open it in a new VSCode window.
Press Ctrl+Shift+F (Windows/Linux) or Cmd+Shift+F (macOS) to open the Global Search view .
Search for shopify-ai-toolkit and see if any logs have additional details.
Everytime I start VS Code, I don’t think it’s ever actually updated
Nothing Shopify related in that log, the only warning is:
`2026-08-06 15:23:06.564 [warning] updateWindowsJumpList#setJumpList unexpected result: customCategoryAccessDeniedError`
Are you on the latest VSCode? What if you remove / re-add the plugin?
@ceri_waters I’m seeing it reproduce here too, will respond here when we have an update
@ceri_waters We think we’ve identified this as an issue in VSCode, having to do with concurrent attempts to update the git repo for the plugin:
opened 12:47AM - 07 Aug 26 UTC
# Agent plugins: auto-update permanently fails with "Cannot fast-forward to mult… iple branches" (concurrent git fetch/pull in the same plugin clone)
- VS Code Version: Version: 1.132.0 (Universal), Commit: df53daabb18cd157bdb08c7f01c34df936cf12f4
- OS Version: macOS 26.3.1 (a) (25D771280a), Apple Silicon (also reported on Windows 11)
- Feature: Agent plugins (preview), plugin installed via `Chat: Install Plugin From Source`
## Steps to Reproduce
1. Enable the agent plugins preview.
2. Run `Chat: Install Plugin From Source` and enter a public git URL (repro repo: `https://github.com/Shopify/shopify-ai-toolkit`).
3. Let the upstream repo advance by at least one commit.
4. Restart VS Code. Having a second window (or the Sessions app) open makes it reproduce reliably.
## Expected
The cached plugin clone fast-forwards to the new upstream commit.
## Actual
An error notification appears on every launch:
> Failed to update: https://github.com/Shopify/shopify-ai-toolkit [Show Output]
The plugin never updates again. The state is self-perpetuating: because the update never lands, the clone stays behind, so every subsequent launch has commits to fetch and fails the same way. Two independent users (macOS and Windows 11) report the plugin has never successfully updated since install.
`Show Output` opens the built-in Git extension's output channel, which contains nothing related to plugin updates, so the failure is undiagnosable from the UI.
## Logs
From `sharedprocess.log` (the only place the real error appears):
```
2026-08-06 13:09:52.018 [error] [LocalGitService] git fetch failed: Command failed: git fetch
error: cannot lock ref 'refs/remotes/origin/main': is at cc5af6505c27939222072449278f6356857cb064 but expected 0e06bc35611e505e372de7f8cdf265e6d6dbc311
From https://github.com/Shopify/shopify-ai-toolkit
! 0e06bc3..cc5af65 main -> origin/main (unable to update local ref)
* [new branch] mirror/d8475f49b6ea -> origin/mirror/d8475f49b6ea
2026-08-06 13:09:52.101 [error] [LocalGitService] git fetch failed: Command failed: git fetch
error: cannot lock ref 'refs/remotes/origin/main': is at cc5af6505c27939222072449278f6356857cb064 but expected 0e06bc35611e505e372de7f8cdf265e6d6dbc311
From https://github.com/Shopify/shopify-ai-toolkit
! 0e06bc3..cc5af65 main -> origin/main (unable to update local ref)
* [new branch] mirror/d8475f49b6ea -> origin/mirror/d8475f49b6ea
2026-08-06 13:09:52.912 [error] [LocalGitService] git pull failed: Command failed: git pull --ff-only
fatal: Cannot fast-forward to multiple branches.
```
## Analysis
**1. Concurrent git operations in the same clone.** Two `git fetch` processes fail to lock `refs/remotes/origin/main` 83ms apart, both holding the pre-fetch value, which means a third fetch had already advanced the ref. So at least three `git fetch` processes were running in the same working directory at once.
`AgentPluginRepositoryService` serializes only *clones*:
```ts
private readonly _cloneSequencer = new SequencerByKey<string>();
...
return this._cloneSequencer.queue(repoDir.fsPath, async () => { ... }); // ensureRepository only
```
`pullRepository` and `fetchRepository` take no such lock, and `PluginInstallService.updateAll` fans its per-plugin git work out with `Promise.all(independentGitTasks)` (plus a separate `Promise.all(gitTasks)` for grouped ones). Several plugins/marketplaces backed by the same repository, an update check running alongside an update, or a second window / the Sessions app sharing the same `agent-plugins` directory all produce concurrent `git fetch`/`git pull` in one clone.
**2. Why it becomes a hard failure.** Each `git fetch` truncates and rewrites `FETCH_HEAD`. Concurrent fetches interleave, leaving more than one entry *not* marked `not-for-merge`. `git pull --ff-only` then reads that file and dies in `builtin/pull.c`:
```c
if (merge_heads.nr > 1) {
if (opt_rebase)
die(_("Cannot rebase onto multiple branches."));
if (opt_ff && !strcmp(opt_ff, "--ff-only"))
die(_("Cannot fast-forward to multiple branches."));
}
```
A single, uncontended fetch can never produce this. A manual sequential `git pull --ff-only` in the same clone succeeds immediately.
**3. The recovery path misses it.** `LocalGitService._isFastForwardPullFailure` requires exit code 128 *and* `/not possible to fast-forward|non-fast-forward/i`. `fatal: Cannot fast-forward to multiple branches.` matches neither, so the error is rethrown before the fetch-and-retry and before the `allowHardResetOnDivergence` hard reset that would otherwise repair the clone.
**4. The failure is undiagnosable from the UI.** The notification drops the underlying error:
```ts
message: localize('updateAllFailed', "Failed to update: {0}", failedNames.join(', ')),
actions: {
primary: [new Action('showGitOutput', localize('showOutput', "Show Output"), undefined, true, () => {
this._commandService.executeCommand('git.showOutput');
})],
}
```
`git.showOutput` opens the built-in Git extension's channel, but plugin updates run through `LocalGitService` in the shared process and never write there. Users see an empty/irrelevant log and have no way to reach the real error short of grepping `sharedprocess.log` for `LocalGitService`.
## Suggested fixes
1. Serialize git operations per repository directory, not just clones: reuse `SequencerByKey` keyed on `repoDir.fsPath` for `pullRepository`/`fetchRepository` as well. Because multiple windows and the Sessions app share the same clone, an on-disk lock is needed to fully close it, not just an in-process sequencer.
2. Avoid `FETCH_HEAD` entirely in `LocalGitService.pull`: `git fetch --prune` followed by `git merge --ff-only @{u}` is immune to this whole class of failure, since the merge head is named explicitly.
3. Treat `Cannot fast-forward to multiple branches` as a recoverable fast-forward failure in `_isFastForwardPullFailure`, so the existing retry/hard-reset recovery can repair the clone.
4. Include `err.message` in the `updateAllFailed` notification, and point its action at the log that actually contains the error rather than at `git.showOutput`.
## Workaround
Quit all VS Code windows (including the Sessions app), then run a single sequential pull in the cached clone:
```
git -C ~/.vscode/agent-plugins/<repo-dir> pull --ff-only
```
It fast-forwards cleanly. The error returns the next time upstream advances.
Meanwhile, the workaround is to close VSCode and run the following whenever you see the error (which will likely be whenever we push an update):
git -C ~/.vscode/agent-plugins/github.com/Shopify/shopify-ai-toolkit pull --ff-only
Thanks @NickWesselman err even pulling fails
PS C:\Users\CM.vscode\agent-plugins\github.com\Shopify\shopify-ai-toolkit> git pull --ff-only
Updating 2de64b6..cc5af65
error: cannot stat 'skills/shopify-polaris-admin-extensions/assets/types/@shopify/ui-extensions-react/2025.7.4/build/ts/surfaces/admin/components/InternalCustomerSegmentTemplate/InternalCustomerSegmentTemplate.d.ts': Filename too long
Lots and lots of errors to do with filename length. Tried a --force as well but no joy.
Edit: Turns out filepaths on windows are restricted to 260 characters
Hi @ceri_waters –
Yeah I was going to suggest that you try enabling long file paths on Windows. In addition to enabling in the registry, you may also need to do
git config --global core.longpaths true
We are going to look at options for reducing file path lengths in AI Toolkit, and will monitor the issue with VSCode. Thanks for reporting!
-Nick
, it’s possible to add a work-around by doing RegEdit - but it’s not a very nice requirement