[Error] [UriError]: cannot call joinPath on URI without path — workspaceRecommendations

[vs-code-engineering]

Error Message

unhandlederror-[UriError]: cannot call joinPath on URI without path

Stack Trace

    at a.joinPath (./src/vs/base/common/uri.ts:362:9)
    at ele.joinPath (./src/vs/base/common/resources.ts:186:13)
    at (anonymous) (./src/vs/browser/workspaceRecommendations.ts:62:0)
    at cye.value (./src/vs/browser/workspaceRecommendations.ts:61:0)
    at E._deliver (./src/vs/base/common/event.ts:1354:12)
    at E._deliverQueue (./src/vs/base/common/event.ts:1365:8)
    at E.fire (./src/vs/base/common/event.ts:1389:8)
    at cye.value (./src/vs/platform/files/common/fileService.ts:74:0)
    at E._deliver (./src/vs/base/common/event.ts:1354:12)
    at E._deliverQueue (./src/vs/base/common/event.ts:1365:8)
    at E.fire (./src/vs/base/common/event.ts:1389:8)
    at (anonymous) (./src/vs/platform/files/common/diskFileSystemProvider.ts:141:37)
    at onChange (./src/vs/workbench/services/files/electron-browser/diskFileSystemProvider.ts:148:0)
    at cye.value (./src/vs/platform/files/common/watcher.ts:218:63)
    at E._deliver (./src/vs/base/common/event.ts:1354:12)
    at E.fire (./src/vs/base/common/event.ts:1385:8)
    at E._deliver (./src/vs/base/common/event.ts:1354:12)
    at E.fire (./src/vs/base/common/event.ts:1385:8)
    at c (./src/vs/base/parts/ipc/common/ipc.ts:689:59)
    at jAt.onResponse (./src/vs/base/parts/ipc/common/ipc.ts:757:47)

Raw Stack Trace (minified)

Error: [UriError]: cannot call joinPath on URI without path     at a.joinPath (out/vs/sessions/sessions.desktop.main.js:406:59221)     at ele.joinPath (out/vs/sessions/sessions.desktop.main.js:406:68517)     at out/vs/sessions/sessions.desktop.main.js:2838:14416     at Array.some (<anonymous>)     at cye.value (out/vs/sessions/sessions.desktop.main.js:2838:14367)     at E._deliver (out/vs/sessions/sessions.desktop.main.js:405:3066)     at E._deliverQueue (out/vs/sessions/sessions.desktop.main.js:405:3155)     at E.fire (out/vs/sessions/sessions.desktop.main.js:405:3490)     at cye.value (out/vs/sessions/sessions.desktop.main.js:4163:27961)     at E._deliver (out/vs/sessions/sessions.desktop.main.js:405:3066)     at E._deliverQueue (out/vs/sessions/sessions.desktop.main.js:405:3155)     at E.fire (out/vs/sessions/sessions.desktop.main.js:405:3490)     at out/vs/sessions/sessions.desktop.main.js:4163:55419     at HYt.onFileChanges (out/vs/sessions/sessions.desktop.main.js:4163:58837)     at cye.value (out/vs/sessions/sessions.desktop.main.js:4163:45810)     at E._deliver (out/vs/sessions/sessions.desktop.main.js:405:3066)     at E.fire (out/vs/sessions/sessions.desktop.main.js:405:3385)     at E._deliver (out/vs/sessions/sessions.desktop.main.js:405:3066)     at E.fire (out/vs/sessions/sessions.desktop.main.js:405:3385)     at c (out/vs/sessions/sessions.desktop.main.js:996:886)     at jAt.onResponse (out/vs/sessions/sessions.desktop.main.js:996:1808)     at jAt.onBuffer (out/vs/sessions/sessions.desktop.main.js:996:1663)     at cye.value (out/vs/sessions/sessions.desktop.main.js:995:1635)     at E._deliver (out/vs/sessions/sessions.desktop.main.js:405:3066)     at E._deliverQueue (out/vs/sessions/sessions.desktop.main.js:405:3155)     at E.fire (out/vs/sessions/sessions.desktop.main.js:405:3490)     at MessagePort._e (out/vs/sessions/sessions.desktop.main.js:403:15509)

Details

Property	Value
Bucket ID	152c86ba-75c8-5abd-c702-a9ea3c617a66
Version	1.115.0-insider
Commit	41dd792b
Last Seen	Tue Apr 14 2026 23:56:48 GMT+0000 (Coordinated Universal Time)
Platforms	Linux, Windows, Mac
Product	Agents

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This issue was automatically created from the VS Code Errors Dashboard

[vs-code-engineering]

Related Error Buckets

These additional error buckets are tracked by this issue (v1.115.0, Agents product):

Bucket	Error Message	Version	Code Path
152c86ba	[UriError] joinPath on URI without path	1.115.0	workspaceRecommendations.ts:62
f6bd80ca	[UriError] joinPath on URI without path	1.115.0	workspaceRecommendations.ts:80

Root cause: Workspace folder URIs in the Agents product lack a path component. The same root cause affects multiple components — see also #310366, #310364, #310367, #310368, #310371, #310370, and #308827.

Generated by errors-agents-triage · ● 13.5M · ◷

[vs-code-engineering]

🔍 Error Investigation

Summary

The error [UriError]: cannot call joinPath on URI without path is thrown when workspaceRecommendations.ts handles a file change event and iterates workspace folders, calling joinPath(folder.uri, '.vscode/extensions') on a folder whose URI (unknown:) has no path component. This is the same root cause as the family of errors tracked in #308827 — workspace folder URIs in the Agents product lack a path component because AgentSessionAdapter._buildWorkspace() uses URI.parse('unknown:') as a fallback when a session has no repository metadata.

Culprit Commit

No single culprit commit was identified. The error bucket history shows this error has been present since at least 1.114.0-insider (first seen 2026-03-27) across all insider versions through 1.116.0. This is a systemic issue in the Agents workspace model, not a single-commit regression. The URI.parse('unknown:') fallback at copilotChatSessionsProvider.ts:978 has existed since the sessions workspace infrastructure was introduced.

Code Flow

sequenceDiagram
    participant IPC as File Watcher (IPC)
    participant FS as FileService
    participant WR as WorkspaceRecommendations
    participant ExtUri as extUri.joinPath
    participant URI as URI.joinPath

    IPC->>FS: onDidFilesChange
    FS->>WR: onDidFilesChange(e)
    WR->>WR: getWorkspace().folders.some(folder => ...)
    Note over WR: Iterates ALL workspace folders<br/>including folder with URI 'unknown:'
    WR->>ExtUri: joinPath(folder.uri, '.vscode/extensions')
    ExtUri->>URI: URI.joinPath(URI.parse('unknown:'), ...)
    Note over URI: 💥 [UriError]: cannot call<br/>joinPath on URI without path
    Note over WR: ⚠️ Root cause: _buildWorkspace()<br/>uses URI.parse('unknown:') fallback<br/>when session has no repo metadata

Loading

Affected Files

File	Role
src/vs/sessions/contrib/copilotChatSessions/browser/copilotChatSessionsProvider.ts	Root cause — _buildWorkspace() (line 978) uses URI.parse('unknown:') (no path) as fallback when session has no repository metadata
src/vs/sessions/contrib/workspace/browser/workspaceFolderManagement.ts	Data flow — getActiveSessionFolderData() passes the unknown: URI through as a workspace folder URI without validating it has a path
src/vs/workbench/contrib/extensions/browser/workspaceRecommendations.ts	Crash site — line 61-62: onDidFilesChange handler calls joinPath(folder.uri, '.vscode/extensions') on all workspace folders
src/vs/workbench/contrib/extensions/browser/workspaceRecommendations.ts	Crash site (2nd bucket f6bd80ca) — line 80: fetchWorkspaceExtensions() calls joinPath(workspaceFolder.uri, '.vscode/extensions')
src/vs/base/common/uri.ts	Throw site — URI.joinPath() line 362 throws when URI has no path

Repro Steps

1. Open the VS Code Agents (sessions) application
2. Have an active session whose metadata does not include repository information (no repositoryPath, workingDirectoryPath, or cloud repo metadata)
3. The session's workspace folder is created with a unknown: URI (no path component)
4. Any file change event fires (e.g., from MCP tool registration, schema association changes, or actual filesystem activity)
5. WorkspaceRecommendations.onDidFilesChange iterates all workspace folders and calls joinPath(folder.uri, '.vscode/extensions'), which throws on the pathless URI

The error is deterministic once a session without repo metadata becomes active — it triggers on every file change event. Telemetry shows 16,600 hits from 104 users on version 1.115.0 alone (commit 41dd792b).

Fix Proposal

Fix location: src/vs/sessions/contrib/copilotChatSessions/browser/copilotChatSessionsProvider.ts → _buildWorkspace()

Approach: This is the same root cause as #308827 and should be addressed together. The fix should either:

1. Preferred: Change the fallback URI to include a root path: URI.from({ scheme: 'unknown', path: '/' }) — this ensures joinPath can operate without throwing, fixing all 8+ downstream call paths at once.
2. Alternative: Return undefined from _buildWorkspace() when repoUri is undefined, preventing a workspace folder from being created at all for sessions without repository metadata. The method signature already allows undefined.
3. Defense in depth: Add a guard in workspaceFolderManagement.ts → getActiveSessionFolderData() to reject URIs without a path (if (!repository.path) return undefined).

Recommended Owner

@sandy081 — Already assigned to the parent issue #308827 with the same root cause. Primary maintainer of the sessions workspace management layer and copilotChatSessionsProvider.ts.

Generated by errors-investigate · ● 6M · ◷