build: set netgo & osusergo tags for Linux build (#10261)

Avoid:

/_/GOROOT/src/os/user/cgo_lookup_cgo.go:45:(.text+0x54): warning: Using
'getgrgid_r' in statically linked applications requires at runtime the
shared libraries from the glibc version used for linking

and

/tmp/go-build/cgo-gcc-prolog:60:(.text+0x40): warning: Using
'getaddrinfo' in statically linked applications requires at runtime the
shared libraries from the glibc version used for linking

.github/workflows/build-syncthing.yaml

@@ -27,6 +27,7 @@ env:
   BUILD_HOST: github.syncthing.net
 
   TAGS: "sqlite_omit_load_extension sqlite_dbstat"
+  TAGS_LINUX: "sqlite_omit_load_extension sqlite_dbstat netgo osusergo"
 
 # A note on actions and third party code... The actions under actions/ (like
 # `uses: actions/checkout`) are maintained by GitHub, and we need to trust
@@ -310,19 +311,19 @@ jobs:
         run: |
           sudo apt-get install -y gcc-mips64-linux-gnuabi64 gcc-mips64el-linux-gnuabi64
           for tgt in syncthing stdiscosrv strelaysrv ; do
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch amd64 -cc "zig cc -target x86_64-linux-musl" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch 386 -cc "zig cc -target x86-linux-musl" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch arm -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch arm64 -cc "zig cc -target aarch64-linux-musl" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch mips -cc "zig cc -target mips-linux-musleabi" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch mipsle -cc "zig cc -target mipsel-linux-musleabi" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch mips64 -cc mips64-linux-gnuabi64-gcc tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch mips64le -cc mips64el-linux-gnuabi64-gcc tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch riscv64 -cc "zig cc -target riscv64-linux-musl" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch s390x -cc "zig cc -target s390x-linux-musl" tar "$tgt"
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch loong64 -cc "zig cc -target loongarch64-linux-musl" tar "$tgt"
-            # go run build.go -tags "${{env.TAGS}}" -goos linux -goarch ppc64 -cc "zig cc -target powerpc64-linux-musl" tar "$tgt" # fails with linkmode not supported
-            go run build.go -tags "${{env.TAGS}}" -goos linux -goarch ppc64le -cc "zig cc -target powerpc64le-linux-musl" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch amd64 -cc "zig cc -target x86_64-linux-musl" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch 386 -cc "zig cc -target x86-linux-musl" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch arm -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch arm64 -cc "zig cc -target aarch64-linux-musl" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch mips -cc "zig cc -target mips-linux-musleabi" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch mipsle -cc "zig cc -target mipsel-linux-musleabi" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch mips64 -cc mips64-linux-gnuabi64-gcc tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch mips64le -cc mips64el-linux-gnuabi64-gcc tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch riscv64 -cc "zig cc -target riscv64-linux-musl" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch s390x -cc "zig cc -target s390x-linux-musl" tar "$tgt"
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch loong64 -cc "zig cc -target loongarch64-linux-musl" tar "$tgt"
+            # go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch ppc64 -cc "zig cc -target powerpc64-linux-musl" tar "$tgt" # fails with linkmode not supported
+            go run build.go -tags "${{env.TAGS_LINUX}}" -goos linux -goarch ppc64le -cc "zig cc -target powerpc64le-linux-musl" tar "$tgt"
           done
         env:
           CGO_ENABLED: "1"
@@ -704,10 +705,10 @@ jobs:
       - name: Package for Debian (CGO)
         run: |
           for tgt in syncthing stdiscosrv strelaysrv ; do
-            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS}}" -goos linux -goarch amd64 -cc "zig cc -target x86_64-linux-musl" deb "$tgt"
-            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS}}" -goos linux -goarch armel -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" deb "$tgt"
-            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS}}" -goos linux -goarch armhf -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" deb "$tgt"
-            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS}}" -goos linux -goarch arm64 -cc "zig cc -target aarch64-linux-musl" deb "$tgt"
+            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS_LINUX}}" -goos linux -goarch amd64 -cc "zig cc -target x86_64-linux-musl" deb "$tgt"
+            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS_LINUX}}" -goos linux -goarch armel -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" deb "$tgt"
+            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS_LINUX}}" -goos linux -goarch armhf -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" deb "$tgt"
+            go run build.go -no-upgrade -installsuffix=no-upgrade -tags "${{env.TAGS_LINUX}}" -goos linux -goarch arm64 -cc "zig cc -target aarch64-linux-musl" deb "$tgt"
           done
         env:
           BUILD_USER: debian
@@ -993,15 +994,15 @@ jobs:
       - name: Build binaries (CGO)
         run: |
           # amd64
-          go run build.go -goos linux -goarch amd64 -tags "${{env.TAGS}}" -cc "zig cc -target x86_64-linux-musl" -no-upgrade build ${{ matrix.pkg }}
+          go run build.go -goos linux -goarch amd64 -tags "${{env.TAGS_LINUX}}" -cc "zig cc -target x86_64-linux-musl" -no-upgrade build ${{ matrix.pkg }}
           mv ${{ matrix.pkg }} ${{ matrix.pkg }}-linux-amd64
 
           # arm64
-          go run build.go -goos linux -goarch arm64 -tags "${{env.TAGS}}" -cc "zig cc -target aarch64-linux-musl" -no-upgrade build ${{ matrix.pkg }}
+          go run build.go -goos linux -goarch arm64 -tags "${{env.TAGS_LINUX}}" -cc "zig cc -target aarch64-linux-musl" -no-upgrade build ${{ matrix.pkg }}
           mv ${{ matrix.pkg }} ${{ matrix.pkg }}-linux-arm64
 
           # arm
-          go run build.go -goos linux -goarch arm -tags "${{env.TAGS}}" -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" -no-upgrade build ${{ matrix.pkg }}
+          go run build.go -goos linux -goarch arm -tags "${{env.TAGS_LINUX}}" -cc "zig cc -target arm-linux-musleabi -mcpu=arm1136j_s" -no-upgrade build ${{ matrix.pkg }}
           mv ${{ matrix.pkg }} ${{ matrix.pkg }}-linux-arm
         env:
           CGO_ENABLED: "1"

lib/build/build.go

@@ -49,6 +49,8 @@ var (
 	replaceTags = map[string]string{
 		"sqlite_omit_load_extension": "",
 		"sqlite_dbstat":              "",
+		"netgo":                      "",
+		"osusergo":                   "",
 	}
 )
 
@@ -132,6 +134,7 @@ func TagsList() []string {
 		tags = tags[1:]
 	}
 
+	tags = slices.Compact(tags)
 	return tags
 }