x/mobile: Fails on FreeBSD

[rwestlund]

gomobile init fails on FreeBSD when fetching NDK.

./bin/gomobile: error fetching https://dl.google.com/go/mobile/gomobile-ndk-r12b-freebsd-x86_64.tar.gz, status: 404 Not Found

Looks like there isn't a FreeBSD build. I can't find any instructions for manually doing what gomobile init is doing.

Version:

go version go1.6.2 freebsd/amd64

Env:

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="freebsd"
GOOS="freebsd"
GOPATH="/usr/home/randy/code/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/freebsd_amd64"
GO15VENDOREXPERIMENT="1"
CC="cc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
CXX="clang++"
CGO_ENABLED="1"

[minux]

I don't think it's a gomobile bug. Android doesn't provide Android NDK for FreeBSD.

[rwestlund]

I looked into it more and you're right. However, the Linux version should work under FreeBSD's Linux compatibility layer; FreeBSD provides a full Linux userland. When I set goos = "linux" to make it download the Linux version, I get this error:

randy@mako ~/c/go> ./bin/gomobile init
ELF interpreter /lib64/ld-linux-x86-64.so.2 not found, error 2
./bin/gomobile: go install -gcflags=-shared -ldflags=-shared -pkgdir=/usr/home/randy/code/go/pkg/gomobile/pkg_android_amd64 std failed: exit status 1
go build runtime/cgo: /usr/local/go/pkg/tool/freebsd_amd64/cgo: exit status 2

/lib64/ld-linux-x86-64.so.2 is not the right path on FreeBSD. Let me see whether I can get this working.

[rwestlund]

I have gomobile working on FreeBSD with the following small patch. The Linux version of NDK works under FreeBSD's Linux emulation layer.

--- init.go.orig        2016-09-07 22:25:25.972598863 -0400
+++ init.go     2016-09-07 22:26:26.739591760 -0400
@@ -402,6 +402,8 @@
                "android-%s/toolchains/llvm/prebuilt", ndkVersion))
        if goos == "windows" && ndkarch == "x86" {
                llvmsrc = filepath.Join(llvmsrc, "windows")
+    } else if goos == "freebsd" {
+               llvmsrc = filepath.Join(llvmsrc, "linux-"+ndkarch)
        } else {
                llvmsrc = filepath.Join(llvmsrc, goos+"-"+ndkarch)
        }
@@ -431,6 +433,8 @@
                        "android-%s/toolchains/%s/prebuilt", ndkVersion, toolchain.gcc))
                if goos == "windows" && ndkarch == "x86" {
                        ndkpath = filepath.Join(ndkpath, "windows")
+        } else if goos == "freebsd" {
+                       ndkpath = filepath.Join(ndkpath, "linux-"+ndkarch)
                } else {
                        ndkpath = filepath.Join(ndkpath, goos+"-"+ndkarch)
                }
@@ -467,7 +471,13 @@
 }

 func fetchStrippedNDK() error {
-       url := "https://dl.google.com/go/mobile/gomobile-" + ndkVersion + "-" + goos + "-" + ndkarch + ".tar.gz"
+    var url string;
+    // To support FreeBSD, use the Linux version under 64-bit linux emulation.
+    if goos == "freebsd" {
+           url = "https://dl.google.com/go/mobile/gomobile-" + ndkVersion + "-linux-" + ndkarch + ".tar.gz"
+    } else {
+           url = "https://dl.google.com/go/mobile/gomobile-" + ndkVersion + "-" + goos + "-" + ndkarch + ".tar.gz"
+    }
        archive, err := fetch(url)
        if err != nil {
                return err
@@ -476,7 +486,13 @@
 }

 func fetchFullNDK() error {
-       url := "https://dl.google.com/android/repository/android-" + ndkVersion + "-" + goos + "-" + ndkarch + ".zip"
+    // To support FreeBSD, use the Linux version under 64-bit linux emulation.
+    var url string;
+    if goos == "freebsd" {
+           url = "https://dl.google.com/android/repository/android-" + ndkVersion + "-linux-" + ndkarch + ".zip"
+    } else {
+           url = "https://dl.google.com/android/repository/android-" + ndkVersion + "-" + goos + "-" + ndkarch + ".zip"
+    }
        archive, err := fetch(url)
        if err != nil {
                return err

To run on FreeBSD with this patch:

• Set DEFAULT_VERSIONS+=linux=c7_64 in /etc/make.conf
• Install /usr/ports/emulation/linux_base-c7
• Copy a libc++.so from a recent Linux repo into /compat/linux/lib64

The gomobile tool will now work as normal.

I've created a PR upstream for proper NDK support on FreeBSD. If that ever happens, this patch will not be necessary.
https://code.google.com/p/android/issues/detail?id=221683

[eliasnaur]

Is this still a problem? Much has happened since this was reported. For example, gomobile doesn't download the NDK anymore.