cmd/go/internal/work: set Incomplete to true if there is an error

Fixes #57724

Change-Id: I3d419985ff41d5ee93bb56d8c7ca5cd1d7231920
Reviewed-on: https://go-review.googlesource.com/c/go/+/536418
Auto-Submit: Bryan Mills <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Run-TryBot: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: quantonganh

src/cmd/go/internal/work/exec.go

@@ -164,6 +164,7 @@ func (b *Builder) Do(ctx context.Context, root *Action) {
 			if b.AllowErrors && a.Package != nil {
 				if a.Package.Error == nil {
 					a.Package.Error = &load.PackageError{Err: err}
+					a.Package.Incomplete = true
 				}
 			} else {
 				var ipe load.ImportPathError

src/cmd/go/testdata/script/list_export_e.txt

@@ -6,6 +6,10 @@ go list -f '{{with .Error}}{{.}}{{end}}' -e -export ./...
 ! stderr '.'
 stdout '^# example.com/p2\np2'${/}'main\.go:7:.*'
 
+go list -export -e -f '{{.ImportPath}} -- {{.Incomplete}} -- {{.Error}}' ./...
+stdout 'example.com/p1 -- false -- <nil>'
+stdout 'example.com/p2 -- true -- # example.com/p2'
+
 go list -e -export -json=Error ./...
 stdout '"Err": "# example.com/p2'