flake: fix WorkspaceSSHExec exit code 1 on Windows shells

ThomasK33 · ThomasK33 · commit 5a5d8d713115 · 2025-09-12T14:32:03.000+02:00
On Windows, the SSH exec path always passed '/c' regardless of shell. When the runner’s shell is PowerShell/pwsh, '/c' is invalid and the command exits 1, producing a flaky failure in WorkspaceSSHExec. Detect the resolved shell and choose the correct caller flag (cmd=/c, powershell/pwsh=-Command, others=-c) so simple commands like 'echo' succeed consistently.

Change-Id: I3ed89f9eefe22dfdf3c981d0bc266c0d75d71e08
Signed-off-by: Thomas Kosiewski &lt;tk@coder.com&gt;
diff --git a/agent/agentssh/agentssh.go b/agent/agentssh/agentssh.go
@@ -917,9 +917,23 @@ func (s *Server) CreateCommand(ctx context.Context, script string, env []string,
 
 	// OpenSSH executes all commands with the users current shell.
 	// We replicate that behavior for IDE support.
+	//
+	// On Windows, the correct caller flag depends on the shell:
+	//  - cmd.exe           -> /c
+	//  - powershell/pwsh  -> -Command
+	//  - other shells (e.g. bash.exe from Git Bash) -> -c
 	caller := "-c"
 	if runtime.GOOS == "windows" {
-		caller = "/c"
+		base := strings.ToLower(filepath.Base(shell))
+		switch {
+		case base == "cmd.exe":
+			caller = "/c"
+		case strings.Contains(base, "powershell") || base == "pwsh.exe":
+			caller = "-Command"
+		default:
+			// Fall back to POSIX-style -c for shells like bash.exe/sh.exe on Windows
+			caller = "-c"
+		}
 	}
 	name := shell
 	args := []string{caller, script}
