x/mobile: gomobile binding failed due to lack of some header file in Android NDK

[ChronosXYZ]

What version of Go are you using (go version)?

$ go version
go version go1.14.4 linux/amd64

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/chronosx/.cache/go-build"
GOENV="/home/chronosx/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/chronosx/Документы/code/golang/"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/snap/go/5830"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/snap/go/5830/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build278490309=/tmp/go-build -gno-record-gcc-switches"

Android NDK version: 21.3.6528147

Gomobile version: gomobile version +4c31acb Sun Mar 29 12:56:38 2020 +0000 (android); androidSDK=

(I'm tried to use Go from Ubuntu repos, not only from Snap)

What did you do?

I'm trying to build some library which written in Go for Android (build AAR file).

gomobile: go build -tags mobile -ldflags -X github.com/yggdrasil-network/yggdrasil-go/src/version.buildName=yggdrasil -X github.com/yggdrasil-network/yggdrasil-go/src/version.buildVersion=0.3.14 -s -w  -buildmode=c-shared -o=/tmp/gomobile-work-131080533/android/src/main/jniLibs/armeabi-v7a/libgojni.so ./gobind failed: exit status 2
# runtime/cgo
gcc_android.c:6:10: fatal error: 'android/log.h' file not found

The file android/log.h exists in Android NDK.

What did you expect to see?

Library will compile successfully (it was compiled fine before).

What did you see instead?

I got the error:

gcc_android.c:6:10: fatal error: 'android/log.h' file not found

[toothrot]

/cc @hyangah

[mirza-s]

@ChronosX88

Are you building under $GOPATH? Building with go modules outside of $GOPATH might be the issue here.

[ChronosXYZ]

@ChronosX88

Are you building under $GOPATH? Building with go modules outside of $GOPATH might be the issue here.

@mirza-s

I'm building the AAR file under $GOPATH, but error still exists.

[ChronosXYZ]

Any updates?

[hajimehoshi]

Have you set ANDROID_NDK_HOME environment variable?

[ChronosXYZ]

Have you set ANDROID_NDK_HOME environment variable?

@hajimehoshi Yes, I've set all necessary environment variables.

ANDROID_NDK_HOME file listing:

[hajimehoshi]

I've never tried to develop Android application on Linux so I don't have a good insight. Does regular Android application development work in your environment?

[ChronosXYZ]

I've never tried to develop Android application on Linux so I don't have a good insight. Does regular Android application development work in your environment?

Yep, regular Android app is building correctly.

[ChronosXYZ]

By the way, I know the location of log.h file (it is under $NDK/sysroot/usr/include/android dir). How to specify include dir for

go/src/runtime/cgo/gcc_android.c

Line 6 in 751c37f

#include <android/log.h>

? May be I should add some env vars, or smth like this?

[ChronosXYZ]

The similar error appears in #14398.

[hajimehoshi]

I don't think we really need it but how about setting C_INCLUDE_PATH?

[subins2000]

I was able to fix this by setting the CC variable : export CC=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/darwin-x86_64/bin/i686-linux-android21-clang for x86