x/mobile: no current JVM

[CanRui-Wu]

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

$ go version
go version go1.12.7 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

go env

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/wucanrui/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/wucanrui/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/Cellar/go/1.12.7/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.12.7/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/0_/j6m36l9s0psg9xm5ggt2_b680000gp/T/go-build347025139=/tmp/go-build -gno-record-gcc-switches -fno-common" 

What did you do?

go get -u golang.org/x/mobile/cmd/...
cd $GOPATH/bin
mv gomobile /usr/local/bin
mv gobind /usr/local/bin
gomobile bind -target=android -v testpkg
gomobile bind -target=android -v ***(mypackage)

What did you expect to see?

Everything is ok.

What did you see instead?

I successfully build two aar files(testpkg.aar ***.aar).

However, both testpkg.aar and ***.aar make the app crash when using asset.Open with the log "I/GoLog: asset: no current JVM".

With API 29, the log before crash is "A/libc: Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 5481 (mygoapplication), pid 4382 (mygoapplication)".

I have tested in android simulator(API 24,28,29) and real device(API 28).

Besides, I did not use (vendor, mod , dev) to manage my package. All I did is to use "go get" and "gomobile bind".

[timcooijmans]

This is caused by the change to make gomobile Android-Q compatible. Can you try to provide the ApplicationContext by using the static method Seq.setContext(Context context) before getting the assets?

[CanRui-Wu]

This is caused by the change to make gomobile Android-Q compatible. Can you try to provide the ApplicationContext by using the static method Seq.setContext(Context context) before getting the assets?

Thank you. I add Seq.setContext(getApplicationContext()) and it works. Do I have to set the context in my app? Why this cannot automatic done by gomobile?

[timcooijmans]

Yes you have to set the context (at least) once in your app or library (for example in the Application.onCreate()-method.

There is no (allowed) method to get the ApplicationContext as a library (such as a gobind-based library). The only option is to let the application provide a reference on initialization of the library. This is now implemented in Seq.setContext(Context context).
Previously gomobile used reflection to statically get the ApplicationContext by using a non-published method. However this method is blacklisted in Android-Q causing warnings and exceptions.

[CanRui-Wu]

Yes you have to set the context (at least) once in your app or library (for example in the Application.onCreate()-method.

There is no (allowed) method to get the ApplicationContext as a library (such as a gobind-based library). The only option is to let the application provide a reference on initialization of the library. This is now implemented in Seq.setContext(Context context).
Previously gomobile used reflection to statically get the ApplicationContext by using a non-published method. However this method is blacklisted in Android-Q causing warnings and exceptions.

Thank you very much for detail instruction. BTW, I find the file 'bind_iosapp.go' do not handle the assets subdirectory. Then, I get an error 'no such file or directory' when I still use asset.Open api in IOS. How can I use asset in IOS by using golang?

[timcooijmans]

I'm sorry I'm not familiar with the asset package on iOS. Please open another issue describing your issue (try to provide an example reproducing the problem) and close this ticket as this issue is resolved.