golang: Add go version 1.21

Go1.21 already has the fifth minor revision (released 2023-12-05) and
should therefore already be sufficiently stable. Furthermore we need it
to fix a bug in a NEO/go dependency [1].

Please find all details in the official release note:

    https://go.dev/doc/go1.21

It was released on 2023-08-08 [2]. Due to the go promise of compatibility
most software should still compile without any problems.

In golang < 1.21 we needed to patch golang to fix
https://github.com/golang/go/issues/42525. In golang 1.21 we still need
to apply a fix, but can't apply the old patch because the code changed.
In golang > 1.21 this problem is already fixed with https://go-review.googlesource.com/c/go/+/520055.

Because of https://github.com/golang/go/commit/092671423cd95eaa6df93eb29442fef41504d097
'TestUnshareMountNameSpace' fails on golang 1.21 [3]. In golang 1.20 this test
was skipped [4]. To fix this failure the additional patch
'skip-unshare-mount-test.patch' has been added.

---

[1] nexedi/wendelin.core!22 (comment 195769)]
[2] https://go.dev/doc/devel/release
[3] --- FAIL: TestUnshareMountNameSpace (0.18s)
    exec_linux_test.go:243: unshare failed: exit status 2
        unshare: mount /tmp/TestUnshareMountNameSpace2210137852/001 failed: 0x1
[4] === RUN TestUnshareMountNameSpace exec_linux_test.go:333: kernel prohibits unshare in unprivileged process, unless using user namespace — SKIP: TestUnshareMountNameSpace (0.00s)

component/golang/buildout.cfg

@@ -30,24 +30,28 @@ environment =
   PATH=${swig:location}/bin:${patch:location}/bin:%(PATH)s
   GOROOT_FINAL=${:location}
   ${:environment-extra}
+patch-options = -p1
+
+[golang-common-pre-1.21]
+<= golang-common
 
 # TestChown currently fails in a user-namespace
 # https://github.com/golang/go/issues/42525
-# the patches apply to go >= 1.12
-patch-options = -p1
-patches =
+# the patches apply to 1.21 > go >= 1.12
+# (in go 1.21 we can't apply it, due to code changes,
+#  in go > 1.21 it's hopefully fixed with
+#  https://github.com/golang/go/commit/9f03e8367d85d75675b2f2e90873e3293799d8aa)
+patches +=
   ${:_profile_base_location_}/skip-chown-tests.patch#d4e3c8ef83788fb2a5d80dd75034786f
 
-
 [golang-common-pre-1.19]
-<= golang-common
+<= golang-common-pre-1.21
 
 # TestSCMCredentials fails in a user-namespace if golang version < 1.19
 # https://github.com/golang/go/issues/42525
 patches +=
   ${:_profile_base_location_}/fix-TestSCMCredentials.patch#1d8dbc97cd579e03fafd8627d48f1c59
 
-
 [golang14]
 <= golang-common-pre-1.19
 # https://golang.org/doc/install/source#bootstrapFromSource
@@ -117,13 +121,28 @@ environment-extra =
   GOROOT_BOOTSTRAP=${golang14:location}
 
 [golang1.20]
-<= golang-common
+<= golang-common-pre-1.21
 url = https://go.dev/dl/go1.20.6.src.tar.gz
 md5sum = 1dc2d18790cfaede7df1e73a1eff8b7b
 # go1.20 requires go1.17.13 to bootstrap (see https://go.dev/doc/go1.20#bootstrap)
 environment-extra =
   GOROOT_BOOTSTRAP=${golang1.17:location}
 
+[golang1.21]
+<= golang-common
+url = https://go.dev/dl/go1.21.5.src.tar.gz
+md5sum = 99385ded31906f1554c27015bbbee52d
+# go1.21 requires go1.17.13 to bootstrap (see https://go.dev/blog/rebuild)
+environment-extra =
+  GOROOT_BOOTSTRAP=${golang1.17:location}
+
+patches +=
+# TestChown fix, old fix doesn't work due to code change,
+# for golang > 1.21 this patch is hopefully already included with
+# https://github.com/golang/go/commit/9f03e8367d85d75675b2f2e90873e3293799d8aa
+  ${:_profile_base_location_}/os-skip-Chown-tests-for-auxiliary-groups-that-fail-d.patch#81b7f75786d9024049c26d1663b79ba4
+  ${:_profile_base_location_}/skip-unshare-mount-test.patch#325446d5135452e8685e95ab99c13a51
+
 # ---- infrastructure to build Go workspaces / projects ----
 
 # gowork is the top-level section that defines Go workspace.

component/golang/os-skip-Chown-tests-for-auxiliary-groups-that-fail-d.patch

+From 9f03e8367d85d75675b2f2e90873e3293799d8aa Mon Sep 17 00:00:00 2001
+From: "Bryan C. Mills" <bcmills@google.com>
+Date: Tue, 15 Aug 2023 18:01:16 -0400
+Subject: [PATCH] os: skip Chown tests for auxiliary groups that fail due to
+ permission errors
+
+This addresses the failure mode described in
+https://git.alpinelinux.org/aports/commit/community/go/tests-filter-overflow-gid.patch?id=9851dde0f5d2a5a50f7f3b5323d1b2ff22e1d028,
+but without special-casing an implementation-specific group ID.
+
+For #62053.
+
+Change-Id: I70b1046837b8146889fff7085497213349cd2bf0
+Reviewed-on: https://go-review.googlesource.com/c/go/+/520055
+Reviewed-by: Ian Lance Taylor <iant@google.com>
+TryBot-Result: Gopher Robot <gobot@golang.org>
+Run-TryBot: Bryan Mills <bcmills@google.com>
+Auto-Submit: Bryan Mills <bcmills@google.com>
+---
+ src/os/os_unix_test.go | 22 ++++++++++++++++++++++
+ 1 file changed, 22 insertions(+)
+
+diff --git a/src/os/os_unix_test.go b/src/os/os_unix_test.go
+index 9041b25471..e4271ff905 100644
+--- a/src/os/os_unix_test.go
++++ b/src/os/os_unix_test.go
+@@ -75,6 +75,12 @@ func TestChown(t *testing.T) {
+ 	t.Log("groups: ", groups)
+ 	for _, g := range groups {
+ 		if err = Chown(f.Name(), -1, g); err != nil {
++			if testenv.SyscallIsNotSupported(err) {
++				t.Logf("chown %s -1 %d: %s (error ignored)", f.Name(), g, err)
++				// Since the Chown call failed, the file should be unmodified.
++				checkUidGid(t, f.Name(), int(sys.Uid), gid)
++				continue
++			}
+ 			t.Fatalf("chown %s -1 %d: %s", f.Name(), g, err)
+ 		}
+ 		checkUidGid(t, f.Name(), int(sys.Uid), g)
+@@ -123,6 +129,12 @@ func TestFileChown(t *testing.T) {
+ 	t.Log("groups: ", groups)
+ 	for _, g := range groups {
+ 		if err = f.Chown(-1, g); err != nil {
++			if testenv.SyscallIsNotSupported(err) {
++				t.Logf("chown %s -1 %d: %s (error ignored)", f.Name(), g, err)
++				// Since the Chown call failed, the file should be unmodified.
++				checkUidGid(t, f.Name(), int(sys.Uid), gid)
++				continue
++			}
+ 			t.Fatalf("fchown %s -1 %d: %s", f.Name(), g, err)
+ 		}
+ 		checkUidGid(t, f.Name(), int(sys.Uid), g)
+@@ -181,12 +193,22 @@ func TestLchown(t *testing.T) {
+ 	t.Log("groups: ", groups)
+ 	for _, g := range groups {
+ 		if err = Lchown(linkname, -1, g); err != nil {
++			if testenv.SyscallIsNotSupported(err) {
++				t.Logf("lchown %s -1 %d: %s (error ignored)", f.Name(), g, err)
++				// Since the Lchown call failed, the file should be unmodified.
++				checkUidGid(t, f.Name(), int(sys.Uid), gid)
++				continue
++			}
+ 			t.Fatalf("lchown %s -1 %d: %s", linkname, g, err)
+ 		}
+ 		checkUidGid(t, linkname, int(sys.Uid), g)
+ 
+ 		// Check that link target's gid is unchanged.
+ 		checkUidGid(t, f.Name(), int(sys.Uid), int(sys.Gid))
++
++		if err = Lchown(linkname, -1, gid); err != nil {
++			t.Fatalf("lchown %s -1 %d: %s", f.Name(), gid, err)
++		}
+ 	}
+ }
+ 
+-- 
+2.36.0
+

component/golang/skip-unshare-mount-test.patch

+https://github.com/golang/go/commit/092671423cd95eaa6df93eb29442fef41504d097 breaks
+TestUnshareMountNameSpace test on SlapOS.
+---
+diff --git a/src/syscall/exec_linux_test.go b/src/syscall/exec_linux_test.go
+index f4ff7bf81b..bc8bdb0a35 100644
+--- a/src/syscall/exec_linux_test.go
++++ b/src/syscall/exec_linux_test.go
+@@ -206,6 +206,7 @@ func TestGroupCleanupUserNamespace(t *testing.T) {
+ // Test for https://go.dev/issue/19661: unshare fails because systemd
+ // has forced / to be shared
+ func TestUnshareMountNameSpace(t *testing.T) {
++    t.Skip("skipping: not supported in SlapOS")
+ 	testenv.MustHaveExec(t)
+ 
+ 	if os.Getenv("GO_WANT_HELPER_PROCESS") == "1" {