diff --git a/cue/builtin.go b/cue/builtin.go
index 4a680bb..a13d384 100644
--- a/cue/builtin.go
+++ b/cue/builtin.go
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 //go:generate go run gen.go
-//go:generate goimports -w -local cuelang.org/go builtins.go
+//go:generate go run golang.org/x/tools/cmd/goimports -w -local cuelang.org/go builtins.go
 //go:generate gofmt -s -w builtins.go
 
 package cue
diff --git a/cue/builtins.go b/cue/builtins.go
index 1dd46a7..0957474 100644
--- a/cue/builtins.go
+++ b/cue/builtins.go
@@ -3121,10 +3121,10 @@
 			Params: []kind{listKind, stringKind},
 			Result: stringKind,
 			Func: func(c *callCtxt) {
-				a, sep := c.strList(0), c.string(1)
+				elems, sep := c.strList(0), c.string(1)
 				if c.do() {
 					c.ret = func() interface{} {
-						return strings.Join(a, sep)
+						return strings.Join(elems, sep)
 					}()
 				}
 			},
diff --git a/internal/cmd/qgo/qgo.go b/internal/cmd/qgo/qgo.go
index 1f9c942..d1fcbb6 100644
--- a/internal/cmd/qgo/qgo.go
+++ b/internal/cmd/qgo/qgo.go
@@ -80,7 +80,7 @@
 func main() {
 	flag.Parse()
 
-	genLine = "//go:generate " + strings.Join(os.Args, " ")
+	genLine = "//go:generate go run cuelang.org/go/internal/cmd/qgo " + strings.Join(os.Args[1:], " ")
 
 	args := flag.Args()
 	if len(args) == 0 {
diff --git a/pkg/encoding/hex/hex.go b/pkg/encoding/hex/hex.go
index 478632a..4a9fa1a 100644
--- a/pkg/encoding/hex/hex.go
+++ b/pkg/encoding/hex/hex.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -stripstr -exclude=Decode$,Encode$,EncodeToString,Dumper extract encoding/hex
+//go:generate go run cuelang.org/go/internal/cmd/qgo -stripstr -exclude=Decode$,Encode$,EncodeToString,Dumper extract encoding/hex
 
 package hex
 
diff --git a/pkg/encoding/json/json.go b/pkg/encoding/json/json.go
index 3bb0642..2da0b3a 100644
--- a/pkg/encoding/json/json.go
+++ b/pkg/encoding/json/json.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude=Compact,Indent,arshal$ extract encoding/json
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude=Compact,Indent,arshal$ extract encoding/json
 
 package json
 
diff --git a/pkg/html/html.go b/pkg/html/html.go
index 548392b..7f6cefb 100644
--- a/pkg/html/html.go
+++ b/pkg/html/html.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -stripstr extract html
+//go:generate go run cuelang.org/go/internal/cmd/qgo -stripstr extract html
 
 package html
 
diff --git a/pkg/math/big.go b/pkg/math/big.go
index 5f20b82..41b3ffc 100644
--- a/pkg/math/big.go
+++ b/pkg/math/big.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude= extract math/big
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude= extract math/big
 
 package math
 
diff --git a/pkg/path/path.go b/pkg/path/path.go
index fecc049..bd82f26 100644
--- a/pkg/path/path.go
+++ b/pkg/path/path.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude=Split,Join extract path
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude=Split,Join extract path
 
 package path
 
diff --git a/pkg/regexp/regexp.go b/pkg/regexp/regexp.go
index fe34a5d..19dd2c4 100644
--- a/pkg/regexp/regexp.go
+++ b/pkg/regexp/regexp.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude=Compile,Append,Reader,Match$ -stripstr extract regexp
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude=Compile,Append,Reader,Match$ -stripstr extract regexp
 
 package regexp
 
diff --git a/pkg/strconv/strconv.go b/pkg/strconv/strconv.go
index b3e556e..afeca28 100644
--- a/pkg/strconv/strconv.go
+++ b/pkg/strconv/strconv.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude=Append,Unquote,Itoa,CanBackquote extract strconv
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude=Append,Unquote,Itoa,CanBackquote extract strconv
 
 package strconv
 
@@ -155,8 +155,9 @@
 }
 
 // QuoteToGraphic returns a double-quoted Go string literal representing s.
-// The returned string uses Go escape sequences (\t, \n, \xFF, \u0100) for
-// non-ASCII characters and non-printable characters as defined by IsGraphic.
+// The returned string leaves Unicode graphic characters, as defined by
+// IsGraphic, unchanged and uses Go escape sequences (\t, \n, \xFF, \u0100)
+// for non-graphic characters.
 func QuoteToGraphic(s string) string {
 	return strconv.QuoteToGraphic(s)
 }
@@ -177,9 +178,9 @@
 }
 
 // QuoteRuneToGraphic returns a single-quoted Go character literal representing
-// the rune. The returned string uses Go escape sequences (\t, \n, \xFF,
-// \u0100) for non-ASCII characters and non-printable characters as defined
-// by IsGraphic.
+// the rune. If the rune is not a Unicode graphic character,
+// as defined by IsGraphic, the returned string will use a Go escape sequence
+// (\t, \n, \xFF, \u0100).
 func QuoteRuneToGraphic(r rune) string {
 	return strconv.QuoteRuneToGraphic(r)
 }
diff --git a/pkg/strings/strings.go b/pkg/strings/strings.go
index a2077fb..3945718 100644
--- a/pkg/strings/strings.go
+++ b/pkg/strings/strings.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude=Rune$,Func$,^Map$,Special$,EqualFold,Byte,Title$,ToValidUTF8,All$ extract strings
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude=Rune$,Func$,^Map$,Special$,EqualFold,Byte,Title$,ToValidUTF8,All$ extract strings
 
 package strings
 
@@ -129,10 +129,10 @@
 	return strings.Fields(s)
 }
 
-// Join concatenates the elements of a to create a single string. The separator string
-// sep is placed between elements in the resulting string.
-func Join(a []string, sep string) string {
-	return strings.Join(a, sep)
+// Join concatenates the elements of its first argument to create a single string. The separator
+// string sep is placed between elements in the resulting string.
+func Join(elems []string, sep string) string {
+	return strings.Join(elems, sep)
 }
 
 // HasPrefix tests whether the string s begins with prefix.
diff --git a/pkg/text/template/template.go b/pkg/text/template/template.go
index 9e2eab1..2784e5c 100644
--- a/pkg/text/template/template.go
+++ b/pkg/text/template/template.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The CUE Authors
+// Copyright 2020 The CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate qgo -exclude=Escaper$,Must,Parse -stripstr extract text/template
+//go:generate go run cuelang.org/go/internal/cmd/qgo -exclude=Escaper$,Must,Parse -stripstr extract text/template
 
 package template
 
diff --git a/pkg/tool/cli/cli.go b/pkg/tool/cli/cli.go
index dd29681..8ba4878 100644
--- a/pkg/tool/cli/cli.go
+++ b/pkg/tool/cli/cli.go
@@ -15,6 +15,7 @@
 package cli
 
 //go:generate go run gen.go
+//go:generate gofmt -s -w .
 
 import (
 	"fmt"
diff --git a/pkg/tool/exec/exec.go b/pkg/tool/exec/exec.go
index 7c2db97..62c2cec 100644
--- a/pkg/tool/exec/exec.go
+++ b/pkg/tool/exec/exec.go
@@ -15,6 +15,7 @@
 package exec
 
 //go:generate go run gen.go
+//go:generate gofmt -s -w .
 
 import (
 	"fmt"
diff --git a/pkg/tool/file/file.go b/pkg/tool/file/file.go
index 7514a03..7c206ca 100644
--- a/pkg/tool/file/file.go
+++ b/pkg/tool/file/file.go
@@ -15,6 +15,7 @@
 package file
 
 //go:generate go run gen.go
+//go:generate gofmt -s -w .
 
 import (
 	"io/ioutil"
diff --git a/pkg/tool/http/http.go b/pkg/tool/http/http.go
index eaa77bc..4c6f9e6 100644
--- a/pkg/tool/http/http.go
+++ b/pkg/tool/http/http.go
@@ -15,6 +15,7 @@
 package http
 
 //go:generate go run gen.go
+//go:generate gofmt -s -w .
 
 import (
 	"io"
diff --git a/pkg/tool/os/env.go b/pkg/tool/os/env.go
index 5065ce8..df64b97 100644
--- a/pkg/tool/os/env.go
+++ b/pkg/tool/os/env.go
@@ -15,6 +15,7 @@
 package os
 
 //go:generate go run gen.go
+//go:generate gofmt -s -w .
 
 import (
 	"os"