[release-branch.go1.16] cmd/go: don't report missing std import errors for tidy and...

'go mod tidy' and 'go mod vendor' normally report errors when a
package can't be imported, even if the import appears in a file that
wouldn't be compiled by the current version of Go. These errors are
common for packages introduced in higher versions of Go, like "embed"
in 1.16.

This change causes 'go mod tidy' and 'go mod vendor' to ignore
missing package errors if the import path appears to come from the
standard library because it lacks a dot in the first path element.

Fixes #44793
Updates #27063

Change-Id: I61d6443e77ab95fd8c0d1514f57ef4c8885a77cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/298749
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
(cherry picked from commit 56d52e661114be60fb1893b034ac0c5976b622af)
Reviewed-on: https://go-review.googlesource.com/c/go/+/298949

diff --git a/src/cmd/go/internal/modcmd/tidy.go b/src/cmd/go/internal/modcmd/tidy.go
index 3b83d87a8eb6fecf5693a49891c33fdf16bb672f..8bc9ed50bede7ffcc9069a4b2ff0a4d974a538b8 100644 (file)
--- a/src/cmd/go/internal/modcmd/tidy.go
+++ b/src/cmd/go/internal/modcmd/tidy.go
@@ -62,10 +62,11 @@ func runTidy(ctx context.Context, cmd *base.Command, args []string) {
        modload.RootMode = modload.NeedRoot
 
        modload.LoadPackages(ctx, modload.PackageOpts{
-               Tags:                  imports.AnyTags(),
-               ResolveMissingImports: true,
-               LoadTests:             true,
-               AllowErrors:           tidyE,
+               Tags:                     imports.AnyTags(),
+               ResolveMissingImports:    true,
+               LoadTests:                true,
+               AllowErrors:              tidyE,
+               SilenceMissingStdImports: true,
        }, "all")
 
        modload.TidyBuildList()

diff --git a/src/cmd/go/internal/modcmd/vendor.go b/src/cmd/go/internal/modcmd/vendor.go
index d3ed9e00e229a2021c4d7a4c3ea8a544d0ad654f..ac1fb7720aad4c86e86cfab8a9193fcad4bde4ed 100644 (file)
--- a/src/cmd/go/internal/modcmd/vendor.go
+++ b/src/cmd/go/internal/modcmd/vendor.go
@@ -64,10 +64,11 @@ func runVendor(ctx context.Context, cmd *base.Command, args []string) {
        modload.RootMode = modload.NeedRoot
 
        loadOpts := modload.PackageOpts{
-               Tags:                  imports.AnyTags(),
-               ResolveMissingImports: true,
-               UseVendorAll:          true,
-               AllowErrors:           vendorE,
+               Tags:                     imports.AnyTags(),
+               ResolveMissingImports:    true,
+               UseVendorAll:             true,
+               AllowErrors:              vendorE,
+               SilenceMissingStdImports: true,
        }
        _, pkgs := modload.LoadPackages(ctx, loadOpts, "all")
 

diff --git a/src/cmd/go/internal/modload/load.go b/src/cmd/go/internal/modload/load.go
index 6d87acc6d3b7c9371cdb62e08339b585dd149833..154fc3c6f0afc6bba814240e3504ef0a94d290ed 100644 (file)
--- a/src/cmd/go/internal/modload/load.go
+++ b/src/cmd/go/internal/modload/load.go
@@ -170,6 +170,12 @@ type PackageOpts struct {
        // that occur while loading packages. SilenceErrors implies AllowErrors.
        SilenceErrors bool
 
+       // SilenceMissingStdImports indicates that LoadPackages should not print
+       // errors or terminate the process if an imported package is missing, and the
+       // import path looks like it might be in the standard library (perhaps in a
+       // future version).
+       SilenceMissingStdImports bool
+
        // SilenceUnmatchedWarnings suppresses the warnings normally emitted for
        // patterns that did not match any packages.
        SilenceUnmatchedWarnings bool
@@ -287,8 +293,13 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
                                        sumErr.importerIsTest = importer.testOf != nil
                                }
                        }
+                       silence := opts.SilenceErrors
+                       if stdErr := (*ImportMissingError)(nil); errors.As(pkg.err, &stdErr) &&
+                               stdErr.isStd && opts.SilenceMissingStdImports {
+                               silence = true
+                       }
 
-                       if !opts.SilenceErrors {
+                       if !silence {
                                if opts.AllowErrors {
                                        fmt.Fprintf(os.Stderr, "%s: %v\n", pkg.stackText(), pkg.err)
                                } else {

diff --git a/src/cmd/go/testdata/script/mod_tidy_error.txt b/src/cmd/go/testdata/script/mod_tidy_error.txt
index b6c24ceaf75f245436a0d457fe3aea702050e8e1..395537b1a7177917d95805970163b3c7ff12edd3 100644 (file)
--- a/src/cmd/go/testdata/script/mod_tidy_error.txt
+++ b/src/cmd/go/testdata/script/mod_tidy_error.txt
@@ -4,12 +4,12 @@ env GO111MODULE=on
 # 'go mod tidy' and 'go mod vendor' should not hide loading errors.
 
 ! go mod tidy
-stderr '^issue27063 imports\n\tnonexist: package nonexist is not in GOROOT \(.*\)'
+! stderr 'package nonexist is not in GOROOT'
 stderr '^issue27063 imports\n\tnonexist.example.com: cannot find module providing package nonexist.example.com'
 stderr '^issue27063 imports\n\tissue27063/other imports\n\tother.example.com/nonexist: cannot find module providing package other.example.com/nonexist'
 
 ! go mod vendor
-stderr '^issue27063 imports\n\tnonexist: package nonexist is not in GOROOT \(.*\)'
+! stderr 'package nonexist is not in GOROOT'
 stderr '^issue27063 imports\n\tnonexist.example.com: cannot find module providing package nonexist.example.com'
 stderr '^issue27063 imports\n\tissue27063/other imports\n\tother.example.com/nonexist: cannot find module providing package other.example.com/nonexist'