[PATCH V4] go.bbclass: set buildid to empty string to improve reproducibility

[<changqing.li@windriver.com>]

From: Changqing Li <changqing.li@windriver.com>

Go packages and binaries are stamped with build IDs that record both the
action ID, which is a hash of the inputs to the action that produced the
packages or binary, and the content ID, which is a hash of the action
output, namely the archive or binary itself, Refer [1].

And action ID include hash of modroot, which will include build path,
so this make go package not reproducible.
Refer [2], keying off module path instead of module root directory is a TODO.

[snip of log]
HASH[moduleIndex]: "go1.25.3"
HASH[moduleIndex]: "modroot /build-a/tmp/work/x86-64-v3-wrs-linux/buildah/1.41.5/recipe-sysroot-native/usr/lib/go/src/cmd\n"
HASH[moduleIndex]: "package go1.25.3 go index v2 /build-a/tmp/work/x86-64-v3-wrs-linux/buildah/1.41.5/recipe-sysroot-native/usr/lib/go/src/cmd/buildid\n"
HASH[moduleIndex]: "file buildid.go 2025-10-13 16:08:43 +0000 UTC 1704\n"
HASH[moduleIndex]: "file doc.go 2025-10-13 16:08:43 +0000 UTC 558\n"
HASH[moduleIndex]: 007b9fe2edd5b3232f5c98ae6c46e80a435141cb627ba5418c5314c0cbf4df7b

Report this issue to upstream, refer [3]
Workaround the reproducible by setting buildid to empty, refer [4]

Refer:
[1] https://github.com/golang/go/blob/master/src/cmd/go/internal/work/buildid.go#L26
[2] https://github.com/golang/go/blob/master/src/cmd/go/internal/modindex/read.go#L70
[3] https://github.com/golang/go/issues/77086
[4] https://github.com/golang/go/issues/34186

Signed-off-by: Changqing Li <changqing.li@windriver.com>
---
 meta/classes-recipe/go.bbclass | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/meta/classes-recipe/go.bbclass b/meta/classes-recipe/go.bbclass
index b540471ba2..1c43b36fc0 100644
--- a/meta/classes-recipe/go.bbclass
+++ b/meta/classes-recipe/go.bbclass
@@ -51,11 +51,12 @@ GO_RPATH:class-native = "${@'-r ${STAGING_LIBDIR_NATIVE}/go/pkg/${TARGET_GOTUPLE
 GO_RPATH_LINK:class-native = "${@'-Wl,-rpath-link=${STAGING_LIBDIR_NATIVE}/go/pkg/${TARGET_GOTUPLE}_dynlink' if d.getVar('GO_DYNLINK') else ''}"
 GO_EXTLDFLAGS ?= "${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS} ${GO_RPATH_LINK} ${LDFLAGS}"
 GO_LINKMODE ?= ""
+GO_BUILDID ?= "-buildid="
 GO_EXTRA_LDFLAGS ?= ""
 GO_LINUXLOADER ?= "-I ${@get_linuxloader(d)}"
 # Use system loader. If uninative is used, the uninative loader will be patched automatically
 GO_LINUXLOADER:class-native = ""
-GO_LDFLAGS ?= '-ldflags="${GO_RPATH} ${GO_LINKMODE} ${GO_LINUXLOADER} ${GO_EXTRA_LDFLAGS} -extldflags '${GO_EXTLDFLAGS}'"'
+GO_LDFLAGS ?= '-ldflags="${GO_RPATH} ${GO_LINKMODE} ${GO_LINUXLOADER} ${GO_EXTRA_LDFLAGS} ${GO_BUILDID} -extldflags '${GO_EXTLDFLAGS}'"'
 export GOBUILDFLAGS ?= "-v ${GO_LDFLAGS} -trimpath"
 export GOPATH_OMIT_IN_ACTIONID ?= "1"
 export GOPTESTBUILDFLAGS ?= "${GOBUILDFLAGS} -c"
-- 
2.34.1