Describe the bug
Describe the bug
Copying agent output to the clipboard stopped working on Windows. The copy operation
appears to succeed (no error shown) but paste yields the previous clipboard contents —
the clipboard is not updated. This works correctly in 1.0.48.
Affected version
GitHub Copilot CLI 1.0.57-5.
Run 'copilot update' to check for updates.
Broken: 1.0.55 through 1.0.57 (current stable as of 2026-06-01)
Working: 1.0.48 and below
Not tested: 1.0.49 through 1.0.54 (may work; the first relevant change — cell-based
renderer — appears in 1.0.55)
Affected version
GitHub Copilot CLI 1.0.57-5
Steps to reproduce the behavior
Steps to reproduce the behavior
- Install Copilot CLI 1.0.55 or later on Windows
- Start a session and generate any code or text output
- Attempt to copy the output to the clipboard using the CLI's native copy function
- Attempt to paste elsewhere — clipboard retains its prior content; the copy had no effect
Expected behavior
Expected behavior
The copy function updates the Windows clipboard with the selected agent output, replacing
any prior clipboard content and making it available to paste into other applications.
Additional context
Additional context
Root cause candidate — 1.0.55-6 changelog:
"Cell-based terminal renderer is now enabled for all users by default"
This is the most significant change to the terminal I/O subsystem between 1.0.48 and
1.0.56. The cell-based renderer is a fundamental replacement of the rendering pipeline,
and clipboard operations (OSC 52 escape sequences or system clipboard integration) are
tightly coupled to the rendering layer.
Supporting evidence from the same 1.0.55 release cycle:
- 1.0.55-1: "Clipboard correctly copies CJK and supplementary-plane Unicode characters
on Windows" — this implies the cell-based renderer's Windows clipboard integration was
actively broken during development and required targeted fixes.
The 1.0.55 CJK fix addresses a specific subset of clipboard failures (non-ASCII on
Windows) but the broader copy flow for ASCII/Latin content appears to remain broken.
Why the paste fixes in 1.0.56–1.0.57 do not address this:
Multiple clipboard-related fixes landed in 1.0.56 and 1.0.57 (tab cursor fix, empty
line fix, Wayland fix), but all of these address pasting into the prompt, not
copying from the response.
Workaround: Revert to 1.0.48 (or possibly anything prior to 1.0.55 — versions
1.0.49–1.0.54 not tested).
Environment:
- OS: Windows 11 (Build 26100)
- CPU: x86_64
- Terminal: Cygwin (mintty), cmd.exe in conhost (Start menu) — reproduced in both
- Shell: bash (Cygwin) / cmd
- Node.js: v24.15.0
- Installation:
npm install -g @github/copilot
Related issue: #3621 (auto-compaction loop) — both bugs manifest simultaneously and
both regressed in the 1.0.52–1.0.55 timeframe.
Describe the bug
Describe the bug
Copying agent output to the clipboard stopped working on Windows. The copy operation
appears to succeed (no error shown) but paste yields the previous clipboard contents —
the clipboard is not updated. This works correctly in 1.0.48.
Affected version
Broken: 1.0.55 through 1.0.57 (current stable as of 2026-06-01)
Working: 1.0.48 and below
Not tested: 1.0.49 through 1.0.54 (may work; the first relevant change — cell-based
renderer — appears in 1.0.55)
Affected version
GitHub Copilot CLI 1.0.57-5
Steps to reproduce the behavior
Steps to reproduce the behavior
Expected behavior
Expected behavior
The copy function updates the Windows clipboard with the selected agent output, replacing
any prior clipboard content and making it available to paste into other applications.
Additional context
Additional context
Root cause candidate — 1.0.55-6 changelog:
This is the most significant change to the terminal I/O subsystem between 1.0.48 and
1.0.56. The cell-based renderer is a fundamental replacement of the rendering pipeline,
and clipboard operations (OSC 52 escape sequences or system clipboard integration) are
tightly coupled to the rendering layer.
Supporting evidence from the same 1.0.55 release cycle:
on Windows" — this implies the cell-based renderer's Windows clipboard integration was
actively broken during development and required targeted fixes.
The 1.0.55 CJK fix addresses a specific subset of clipboard failures (non-ASCII on
Windows) but the broader copy flow for ASCII/Latin content appears to remain broken.
Why the paste fixes in 1.0.56–1.0.57 do not address this:
Multiple clipboard-related fixes landed in 1.0.56 and 1.0.57 (tab cursor fix, empty
line fix, Wayland fix), but all of these address pasting into the prompt, not
copying from the response.
Workaround: Revert to 1.0.48 (or possibly anything prior to 1.0.55 — versions
1.0.49–1.0.54 not tested).
Environment:
npm install -g @github/copilotRelated issue: #3621 (auto-compaction loop) — both bugs manifest simultaneously and
both regressed in the 1.0.52–1.0.55 timeframe.