Add any configured Go Workspace file to the config watcher

Fixes #10556

modules/collect.go

@@ -107,9 +107,15 @@ func (h *Client) collect(tidy bool) (ModulesConfig, *collector) {
 		}
 	}*/
 
+	var workspaceFilename string
+	if h.ccfg.ModuleConfig.Workspace != WorkspaceDisabled {
+		workspaceFilename = h.ccfg.ModuleConfig.Workspace
+	}
+
 	return ModulesConfig{
-		AllModules:        c.modules,
-		GoModulesFilename: c.GoModulesFilename,
+		AllModules:          c.modules,
+		GoModulesFilename:   c.GoModulesFilename,
+		GoWorkspaceFilename: workspaceFilename,
 	}, c
 }
 
@@ -122,6 +128,9 @@ type ModulesConfig struct {
 
 	// Set if this is a Go modules enabled project.
 	GoModulesFilename string
+
+	// Set if a Go workspace file is configured.
+	GoWorkspaceFilename string
 }
 
 func (m *ModulesConfig) setActiveMods(logger loggers.Logger) error {

modules/config.go

@@ -15,6 +15,7 @@ package modules
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -261,6 +262,9 @@ func decodeConfig(cfg config.Provider, pathReplacements map[string]string) (Conf
 				workingDir := cfg.GetString("workingDir")
 				c.Workspace = filepath.Join(workingDir, c.Workspace)
 			}
+			if _, err := os.Stat(c.Workspace); err != nil {
+				return c, fmt.Errorf("module workspace %q does not exist", c.Workspace)
+			}
 		}
 	}