cmd/go: re-enable build JSON from go test -json, now with GODEBUG

This re-enables the behavior of CL 536399 (by effectively reverting CL
628955), so now go test -json again includes build output and failures
as JSON rather than text.

However, since this behavior is clearly enough to trip up some build
systems, this CL includes a GODEBUG=gotestjsonbuildtext that can be
set to 1 to revert to the old behavior.

Fixes #70402.
Updates #62067.

Cq-Include-Trybots: luci.golang.try:gotip-darwin-arm64_13,gotip-linux-amd64-longtest,gotip-windows-amd64-longtest
Change-Id: I84e778cd844783dacfc83433e391b5ccb5925127
Reviewed-on: https://go-review.googlesource.com/c/go/+/629335
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Austin Clements <austin@google.com>

diff --git a/doc/godebug.md b/doc/godebug.md
index 7b5fd3e48b87d7c59050c462cd5ba12aae2e8a65..540babf05a11470de376e99905e82784e8eee0eb 100644 (file)
--- a/doc/godebug.md
+++ b/doc/godebug.md
@@ -168,6 +168,14 @@ For Go 1.24, it now defaults to multipathtcp="2", thus
 enabled by default on listerners. Using multipathtcp="0" reverts to the
 pre-Go 1.24 behavior.
 
+Go 1.24 changed the behavior of `go test -json` to emit build errors as JSON
+instead of text.
+These new JSON events are distinguished by new `Action` values,
+but can still cause problems with CI systems that aren't robust to these events.
+This behavior can be controlled with the `gotestjsonbuildtext` setting.
+Using `gotestjsonbuildtext=1` restores the 1.23 behavior.
+This setting will be removed in a future release, Go 1.28 at the earliest.
+
 ### Go 1.23
 
 Go 1.23 changed the channels created by package time to be unbuffered

diff --git a/doc/next/3-tools.md b/doc/next/3-tools.md
index 04e670c2f5fd943256419a468b3cc202649e51cc..5e450c66cedf802d5d7bfe1e47100fe3430739ec 100644 (file)
--- a/doc/next/3-tools.md
+++ b/doc/next/3-tools.md
@@ -4,9 +4,13 @@
 
 The `go build` and `go install` commands now accept a `-json` flag that reports
 build output and failures as structured JSON output on standard output.
-Furthermore, passing `-json` to `go test` now reports build output and failures
-in addition to test results in JSON. For details of the reporting format, see
-`go help buildjson`.
+For details of the reporting format, see `go help buildjson`.
+
+Furthermore, `go test -json` now reports build output and failures in JSON,
+interleaved with test result JSON.
+These are distinguished by new `Action` types, but if they cause problems in
+a test integration system, you can revert to the text build output by setting
+`GODEBUG=gotestjsonbuildtext=1`.
 
 ### Cgo {#cgo}
 

diff --git a/src/cmd/go/internal/test/testflag.go b/src/cmd/go/internal/test/testflag.go
index f91e4e6705b3a0d9747301642d18d897c3ccd036..09e41533b6ccbabd41a0148bb4db3bc4a044d096 100644 (file)
--- a/src/cmd/go/internal/test/testflag.go
+++ b/src/cmd/go/internal/test/testflag.go
@@ -6,11 +6,13 @@ package test
 
 import (
        "cmd/go/internal/base"
+       "cmd/go/internal/cfg"
        "cmd/go/internal/cmdflag"
        "cmd/go/internal/work"
        "errors"
        "flag"
        "fmt"
+       "internal/godebug"
        "os"
        "path/filepath"
        "strconv"
@@ -25,6 +27,8 @@ import (
 // our command line are for us, and some are for the test binary, and
 // some are for both.
 
+var gotestjsonbuildtext = godebug.New("gotestjsonbuildtext")
+
 func init() {
        work.AddBuildFlags(CmdTest, work.OmitVFlag|work.OmitJSONFlag)
 
@@ -33,7 +37,6 @@ func init() {
        cf.StringVar(&testO, "o", "", "")
        work.AddCoverFlags(CmdTest, &testCoverProfile)
        cf.Var((*base.StringsFlag)(&work.ExecCmd), "exec", "")
-       // TODO(austin): Make test -json imply build -json.
        cf.BoolVar(&testJSON, "json", false, "")
        cf.Var(&testVet, "vet", "")
 
@@ -354,8 +357,11 @@ func testFlags(args []string) (packageNames, passToTest []string) {
                delete(addFromGOFLAGS, "v")
                delete(addFromGOFLAGS, "test.v")
 
-               // TODO(austin,#70402): Re-enable this once LUCI can handle build JSON in the test stream.
-               //cfg.BuildJSON = true
+               if gotestjsonbuildtext.Value() == "1" {
+                       gotestjsonbuildtext.IncNonDefault()
+               } else {
+                       cfg.BuildJSON = true
+               }
        }
 
        // Inject flags from GOFLAGS before the explicit command-line arguments.

diff --git a/src/cmd/go/testdata/script/test_json_build.txt b/src/cmd/go/testdata/script/test_json_build.txt
index 9587ebca95f984caaec9bf1ee6a048da34564109..a3f0c37923faf5fb74be61436f349e666f1a2df4 100644 (file)
--- a/src/cmd/go/testdata/script/test_json_build.txt
+++ b/src/cmd/go/testdata/script/test_json_build.txt
@@ -1,8 +1,7 @@
-# TODO(austin,#70402)
-skip
-
 [short] skip
 
+env GODEBUG=gotestjsonbuildtext=0
+
 # There are several places where paths appear in JSON in regexps here.
 # For the path separator we use (/|\\\\).
 # Unfortunately, we can't just use ${/} because, while script test automatically
@@ -52,6 +51,16 @@ stdout '"Action":"output","Package":"m/veterror","Output":"FAIL\\tm/veterror \[b
 stdout '"Action":"fail","Package":"m/veterror","Elapsed":.*,"FailedBuild":"m/veterror \[m/veterror.test\]"'
 ! stderr '.'
 
+# Test that the GODEBUG fallback works.
+env GODEBUG=gotestjsonbuildtext=1
+! go test -json -o=$devnull ./builderror
+stderr '# m/builderror \[m/builderror.test\]\n'
+stderr 'builderror'${/}'main_test.go:3:11: undefined: y\n'
+stdout '"Action":"start","Package":"m/builderror"'
+stdout '"Action":"output","Package":"m/builderror","Output":"FAIL\\tm/builderror \[build failed\]\\n"'
+stdout '"Action":"fail","Package":"m/builderror","Elapsed":.*,"FailedBuild":"m/builderror \[m/builderror\.test\]"'
+
+
 -- go.mod --
 module m
 go 1.21

diff --git a/src/internal/godebugs/table.go b/src/internal/godebugs/table.go
index 59d4fa7d5b87414a77ca0ef68813d4d6deef0df5..d00014eaaef4bb0487062eed5cd9da70cfd80b8f 100644 (file)
--- a/src/internal/godebugs/table.go
+++ b/src/internal/godebugs/table.go
@@ -30,6 +30,7 @@ var All = []Info{
        {Name: "gocachehash", Package: "cmd/go"},
        {Name: "gocachetest", Package: "cmd/go"},
        {Name: "gocacheverify", Package: "cmd/go"},
+       {Name: "gotestjsonbuildtext", Package: "cmd/go", Changed: 24, Old: "1"},
        {Name: "gotypesalias", Package: "go/types", Changed: 23, Old: "0"},
        {Name: "http2client", Package: "net/http"},
        {Name: "http2debug", Package: "net/http", Opaque: true},

diff --git a/src/runtime/metrics/doc.go b/src/runtime/metrics/doc.go
index 906abb4102e674e73a95f81f2980ab58ab6cffa9..cda2c6fc5ef6c71eb0e944492869572816265f43 100644 (file)
--- a/src/runtime/metrics/doc.go
+++ b/src/runtime/metrics/doc.go
@@ -250,6 +250,11 @@ Below is the full list of supported metrics, ordered lexicographically.
                The number of non-default behaviors executed by the cmd/go
                package due to a non-default GODEBUG=gocacheverify=... setting.
 
+       /godebug/non-default-behavior/gotestjsonbuildtext:events
+               The number of non-default behaviors executed by the cmd/go
+               package due to a non-default GODEBUG=gotestjsonbuildtext=...
+               setting.
+
        /godebug/non-default-behavior/gotypesalias:events
                The number of non-default behaviors executed by the go/types
                package due to a non-default GODEBUG=gotypesalias=... setting.