x/mobile: No type or protocol named 'goSeqRefInterface'

[aylesm]

Please answer these questions before submitting your issue. Thanks!

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

go version go1.7.1 darwin/amd64

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

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/michaelayles/Documents/Melrose/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/d2/vr1s6x2j30d52plx6fgy0h480000gn/T/go-build939087427=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

What did you do?

If possible, provide a recipe for reproducing the error.
I've downloaded the latest gomobile version following the instructions online. The version I have now is "gomobile version +2ea7e2c Mon Oct 17 14:21:52 2016 +0000 (android,ios); androidSDK="

I'm trying to build a framework for iOS, which succeeds. But compiling and running against an iOS app fails.

The generated interface contains references that are not defined anywhere.

Error 1: Use of '@import' when modules are disabled

Multiple Errors for every: GoUniverse.h:22:39: No type or protocol named 'goSeqRefInterface'

Example. I've defined a struct in Go:

type Location struct {
    Timestamp int64
    Latitude  float64
    Longitude float64
    Speed     float64
    Course    float64
    Altitude  float64
    Accuracy  float64
}

This generates an interface as this...

@interface GoReachSDKLocation : NSObject <goSeqRefInterface> {
}
@property(strong, readonly) id _ref;

- (id)initWithRef:(id)ref;
- (int64_t)timestamp;
- (void)setTimestamp:(int64_t)v;
- (double)latitude;
- (void)setLatitude:(double)v;
- (double)longitude;
- (void)setLongitude:(double)v;
- (double)speed;
- (void)setSpeed:(double)v;
- (double)course;
- (void)setCourse:(double)v;
- (double)altitude;
- (void)setAltitude:(double)v;
- (double)accuracy;
- (void)setAccuracy:(double)v;
@end

This doesn't compile.

A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

Should compile. Previous version of goMobile didn't use goSeqRefInterface. Output was:

@interface GoReachSDKLocation : NSObject  {
}
@property(strong, readonly) id _ref;

- (id)initWithRef:(id)ref;
- (int64_t)timestamp;
- (void)setTimestamp:(int64_t)v;
- (double)latitude;
- (void)setLatitude:(double)v;
- (double)longitude;
- (void)setLongitude:(double)v;
- (double)speed;
- (void)setSpeed:(double)v;
- (double)course;
- (void)setCourse:(double)v;
- (double)altitude;
- (void)setAltitude:(double)v;
- (double)accuracy;
- (void)setAccuracy:(double)v;
@end

What did you see instead?

Doesn't compile.

[crawshaw]

cc @eliasnaur

[eliasnaur]

The Error 1: Use of '@import' when modules are disabled is probably the culprit. Are modules disabled in your project?

[aylesm]

Modules appear to be enabled. Certainly nothing has changed apart an update to gomobile.

[eliasnaur]

The bind generators have started to use the @import module import syntax, which explains why it fails for you by just upgrading gomobile. However, it should work as long as modules are enabled in your project.

Do the golang.org/x/mobile/example/bind/ios example work for you? I ran

$ gomobile bind -target=ios golang.org/x/mobile/example/bind/hello

in that directory and dragged the resulting Hello.framework into the example project. The example then ran fine in the emulator.

[aylesm]

OK I've found the issue. I was calling my go code from *.mm file. Which despite project settings disables modules. I moved to using a *.m file and my project compiles. Probably worth calling that out in the docs.