[BUG]: failed to run extension

[xbotter]

What happened?

failed to run extension: fork/exec C:\Users\[username]\AppData\Local\GitHub CLI\extensions\gh-copilot\gh-copilot.exe: %1 is not a valid Win32 application.

Versions

Windows 11
PowerShell 7.3.9
gh copilot github/gh-copilot v0.5.2-beta

Relevant terminal output

[imanmahjoubi]

@xbotter Thank you for bringing up this issue and for being an early adopter of this feature. The team will take a look at this. We apologize for the inconvenience 😔

[andyfeller]

@xbotter: I'll need to double check this out later on my personal laptop, but in the mean time, this one has a few of us stumped as Microsoft Windows 11 only supports 64-bit CPUs according to installation site:

Has a 64-bit CPU: Windows 11 can only run on 64-bit CPUs. To see if your PC has one, go to Settings > System > About, or search “System Information” in Windows and look under “System Type.”

In the meantime, could you share the result from printing your system version information?

PS /Users/andyfeller> [System.Environment]::OSVersion

Platform ServicePack Version VersionString
-------- ----------- ------- -------------
    Unix             13.6.1  Unix 13.6.1

As you can see from the release page, we provide distributions for windows-386, windows-amd64, and windows-arm64.

[xbotter]

@andyfeller Thanks for your attention, here is my system version information.

Platform ServicePack Version      VersionString
-------- ----------- -------      -------------
 Win32NT             10.0.22621.0 Microsoft Windows NT 10.0.22621.0

I manually downloaded windows-amd64.exe from the release and replaced the gh-copilot.exe file. It is now working.

[andyfeller]

@andyfeller Thanks for your attention, here is my system version information.

Platform ServicePack Version      VersionString
-------- ----------- -------      -------------
 Win32NT             10.0.22621.0 Microsoft Windows NT 10.0.22621.0

I manually downloaded windows-amd64.exe from the release and replaced the gh-copilot.exe file. It is now working.

Thanks! It appears you are running Windows 10, which has support for 32- and 64-bit exe. I think this is touching on a larger GitHub CLI issue I would love your help in replicating and creating an issue in https://github.com/cli/cli 🙇

I think the problem lays within the extension manager binary extension install logic in determining your platform:

func (m *Manager) installBin(repo ghrepo.Interface, target string) error {
	var r *release
	var err error
	isPinned := target != ""
	if isPinned {
		r, err = fetchReleaseFromTag(m.client, repo, target)
	} else {
		r, err = fetchLatestRelease(m.client, repo)
	}
	if err != nil {
		return err
	}

	platform, ext := m.platform()
	isMacARM := platform == "darwin-arm64"
	trueARMBinary := false

In m.platform(), it is attempting to use Go special variables for your operating system and CPU architecture:

		platform: func() (string, string) {
			ext := ""
			if runtime.GOOS == "windows" {
				ext = ".exe"
			}
			return fmt.Sprintf("%s-%s", runtime.GOOS, runtime.GOARCH), ext
		},

I'd be interested to know which version it downloaded if you still had that info or would be willing to replicate it, so we can dig into that a bit more! 🙇

[xbotter]

@andyfeller I tried to upgrade the CLI and reinstalled the copilot extension, now it's working fine. It might be because my previous CLI version was too old.

[BW404]

I am getting the same issue.

[esilyzhang]

I am getting the same issue.

The issue was resolved by reinstalling it.

gh extension remove github/gh-copilot
gh extension install github/gh-copilot

[orhirshfeld-elbit]

Just Installed Github CLI and Co-pilot on Win11 Powershell and I have the same issue, also tried to reinstall gh-copilot and it didnt work

❯ gh copilot suggest "Install and configure git lfs"
failed to run extension: fork/exec C:\Users\e054310\AppData\Local\GitHub CLI\extensions\gh-copilot\gh-copilot.exe: %1 is not a valid Win32 application.

❯ [System.Environment]::OSVersion

Platform ServicePack Version      VersionString
-------- ----------- -------      -------------
 Win32NT             10.0.26100.0 Microsoft Windows NT 10.0.26100.0

❯ gh --version
gh version 2.78.0 (2025-08-21)
https://github.com/cli/cli/releases/tag/v2.78.0

❯ winget install --id GitHub.cli
Found an existing package already installed. Trying to upgrade the installed package...
No available upgrade found.
No newer package versions are available from the configured sources.

System info:

Processor Intel(R) Core(TM) Ultra 7 165U 2.10 GHz
System type 64-bit operating system, x64-based processor
Edition Windows 11 Enterprise
Version 24H2
OS build 26100.4351

@andyfeller @BW404 @babakks