fix: retry self-upgrade with binary rename on Linux/WSL to avoid ETXTBSY by Copilot · Pull Request #21793 · github/gh-aw

Copilot · 2026-03-19T13:02:09Z

gh aw upgrade fails on Linux/WSL because gh extension upgrade cannot overwrite the gh-aw binary while it is the currently-executing process — the kernel returns ETXTBSY when any process attempts to open() a memory-mapped executable for writing.

Change

The upgrade now uses a try-first, rename-retry strategy to minimize the risk of leaving the installation in a broken state:

First attempt: gh extension upgrade is run directly, without touching the filesystem. On most systems — and on Linux when there is no in-use binary conflict — this succeeds with zero file manipulation.
Rename + retry (Linux only): if the first attempt fails (likely ETXTBSY), the current executable is atomically renamed to a .bak backup path, freeing the original path for gh to write the newly-downloaded binary. The inode remains alive for the running process.
Restore on retry failure: if the retry also fails (network error, permissions, etc.), the backup is automatically renamed back so the user is never left without a working gh-aw installation.
Correct relaunch path: after the rename, os.Executable() returns a "(deleted)"-suffixed path on Linux. upgradeExtensionIfOutdated returns the pre-rename install path, passed directly to relaunchWithSameArgs via a new exeOverride parameter, ensuring the freshly-installed binary is exec'd correctly.

On Linux, the first attempt's output is buffered and suppressed when the rename+retry succeeds, so users do not see a confusing error followed by success.

// renamePathForUpgrade renames exe → exe.bak, freeing the path for the new binary.
// restoreExecutableBackup renames exe.bak → exe if the upgrade fails.
// cleanupExecutableBackup removes exe.bak after a successful upgrade.

No behaviour change on macOS or Windows — the first attempt is the only attempt and no files are renamed.
Rename failure is non-fatal: logged at debug level and the retry proceeds (it may still fail with ETXTBSY, but with an informative error from gh).
If backup restoration itself fails, a user-visible error message is printed with instructions to recover manually.
Helper functions (firstAttemptWriter, renamePathForUpgrade, restoreExecutableBackup, cleanupExecutableBackup) are extracted and covered by unit tests.

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Co-authored-by: dsyme <7204669+dsyme@users.noreply.github.com>

dsyme · 2026-03-19T13:58:20Z

pkg/cli/update_extension_check.go

 	updateExtensionCheckLog.Printf("Upgrading extension from %s to %s", currentVersion, latestVersion)
 	fmt.Fprintln(os.Stderr, console.FormatInfoMessage(fmt.Sprintf("Upgrading gh-aw extension from %s to %s...", currentVersion, latestVersion)))

+	// On Linux (including WSL), the kernel returns ETXTBSY when any process


@pelikhan wdyt, could you look at this? Seems kind of dodgy to delete outselves befor we have a clear understanding the upgrade will succeed?

Replaced the os.Remove approach with os.Rename to a .bak backup in commit 87759d2. If gh extension upgrade succeeds, the backup is cleaned up; if it fails, the backup is automatically restored so the user is never left without gh-aw. The upgrade is only attempted after the rename — we don't proceed blindly without knowing the path is free.

Copilot

Pull request overview

Fixes gh aw upgrade failures on Linux/WSL where gh extension upgrade cannot overwrite the currently-running gh-aw executable due to ETXTBSY (“text file busy”).

Changes:

Add Linux-only pre-upgrade logic to resolve the current executable path and os.Remove() it before invoking gh extension upgrade.
Add debug logging around the pre-removal attempt to aid diagnosis.

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pkg/cli/update_extension_check.go

+	// tries to open a currently-executing binary for writing. Removing the
+	// directory entry (unlink) first avoids this: the inode stays alive while
+	// this process is running, but the path is now free for gh to write the
+	// newly-downloaded binary.
+	if runtime.GOOS == "linux" {
+		if exe, err := os.Executable(); err == nil {
+			// Resolve any symlink so we remove the real file, not just a link.
+			if resolved, resolveErr := filepath.EvalSymlinks(exe); resolveErr == nil {
+				exe = resolved
+			}
+			if rmErr := os.Remove(exe); rmErr != nil {
+				updateExtensionCheckLog.Printf("Could not pre-remove executable before upgrade (upgrade may still fail): %v", rmErr)
+			} else {
+				updateExtensionCheckLog.Printf("Pre-removed executable to avoid ETXTBSY on Linux: %s", exe)


pkg/cli/update_extension_check.go

+			if rmErr := os.Remove(exe); rmErr != nil {
+				updateExtensionCheckLog.Printf("Could not pre-remove executable before upgrade (upgrade may still fail): %v", rmErr)
+			} else {
+				updateExtensionCheckLog.Printf("Pre-removed executable to avoid ETXTBSY on Linux: %s", exe)
+			}


pkg/cli/update_extension_check.go

+	// On Linux (including WSL), the kernel returns ETXTBSY when any process
+	// tries to open a currently-executing binary for writing. Removing the
+	// directory entry (unlink) first avoids this: the inode stays alive while
+	// this process is running, but the path is now free for gh to write the
+	// newly-downloaded binary.
+	if runtime.GOOS == "linux" {
+		if exe, err := os.Executable(); err == nil {
+			// Resolve any symlink so we remove the real file, not just a link.
+			if resolved, resolveErr := filepath.EvalSymlinks(exe); resolveErr == nil {
+				exe = resolved
+			}
+			if rmErr := os.Remove(exe); rmErr != nil {
+				updateExtensionCheckLog.Printf("Could not pre-remove executable before upgrade (upgrade may still fail): %v", rmErr)
+			} else {
+				updateExtensionCheckLog.Printf("Pre-removed executable to avoid ETXTBSY on Linux: %s", exe)
+			}
+		}
+	}


pelikhan · 2026-03-19T17:01:27Z

@copilot review comments

…e failure Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

pelikhan · 2026-03-19T17:57:15Z

@copilot review the risk of bricking the extension and make sure that the copy/swap is done when the new binary is ready and minize potential failure that would break the installation.

…fails Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot · 2026-03-19T18:10:35Z

@copilot review the risk of bricking the extension and make sure that the copy/swap is done when the new binary is ready and minize potential failure that would break the installatio...

Reworked in f37859c. The swap now only happens after the upgrade has already been attempted:

First, try gh extension upgrade directly — no filesystem changes at all (zero bricking risk). On macOS/Windows this is the only path.
Only if the first attempt fails on Linux (likely ETXTBSY): rename the binary to .bak, then retry.
On retry success → clean up .bak.
On retry failure → restore .bak so the user still has a working gh-aw.

The first attempt's error output is buffered on Linux and suppressed when the retry succeeds, so users see a clean experience. The binary is never touched on systems where the upgrade works first time.

Initial plan

61b61b8

Copilot AI assigned Copilot and dsyme Mar 19, 2026

Copilot started work on behalf of dsyme March 19, 2026 13:02 View session

Copilot AI linked an issue Mar 19, 2026 that may be closed by this pull request

gh aw upgrade fails on WSL because it can't update itself while running #21792

Closed

fix: unlink binary before upgrade on Linux/WSL to avoid ETXTBSY (#issue)

d842870

Co-authored-by: dsyme <7204669+dsyme@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix gh aw upgrade failure on WSL due to file in use~~ fix: unlink binary before self-upgrade on Linux/WSL to avoid ETXTBSY Mar 19, 2026

Copilot AI requested a review from dsyme March 19, 2026 13:17

Copilot finished work on behalf of dsyme March 19, 2026 13:17

This was referenced Mar 19, 2026

Smoke Test: Copilot - 23296566936 #21799

Closed

Smoke Test: Copilot - 23296588438 #21801

Closed

Smoke Test: Claude - 23296588401 #21803

Closed

dsyme marked this pull request as ready for review March 19, 2026 13:57

Copilot AI review requested due to automatic review settings March 19, 2026 13:57

dsyme reviewed Mar 19, 2026

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Copilot AI reviewed Mar 19, 2026

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Merge branch 'main' into copilot/fix-gh-aw-upgrade-wsl-error

7e2bd86

Copilot started work on behalf of pelikhan March 19, 2026 17:01 View session

fix: use rename+restore instead of remove to avoid bricking on upgrad…

87759d2

…e failure Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot AI changed the title ~~fix: unlink binary before self-upgrade on Linux/WSL to avoid ETXTBSY~~ fix: rename binary before self-upgrade on Linux/WSL to avoid ETXTBSY Mar 19, 2026

Copilot AI requested a review from pelikhan March 19, 2026 17:16

Copilot finished work on behalf of pelikhan March 19, 2026 17:16

Merge branch 'main' into copilot/fix-gh-aw-upgrade-wsl-error

5bef64b

Copilot started work on behalf of pelikhan March 19, 2026 17:57 View session

fix: try upgrade first, only rename binary on Linux if first attempt …

f37859c

…fails Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot AI changed the title ~~fix: rename binary before self-upgrade on Linux/WSL to avoid ETXTBSY~~ fix: retry self-upgrade with binary rename on Linux/WSL to avoid ETXTBSY Mar 19, 2026

Copilot finished work on behalf of pelikhan March 19, 2026 18:11

Copilot started work on behalf of pelikhan March 19, 2026 18:18 View session

pelikhan merged commit 534d92f into main Mar 19, 2026
102 of 103 checks passed

pelikhan deleted the copilot/fix-gh-aw-upgrade-wsl-error branch March 19, 2026 18:18

Copilot stopped work on behalf of pelikhan due to an error March 19, 2026 18:18
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fix: retry self-upgrade with binary rename on Linux/WSL to avoid ETXTBSY#21793

fix: retry self-upgrade with binary rename on Linux/WSL to avoid ETXTBSY#21793
pelikhan merged 6 commits intomainfrom
copilot/fix-gh-aw-upgrade-wsl-error

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Pull request overview

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