x/mobile/cmd/gomobile: iOS app built with gomobile-build consumes memory and never frees

[hajimehoshi]

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

go version go1.10 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/hajimehoshi/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/hajimehoshi/go"
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
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/7t/qw3np69559591s1v0mk5_p1m0000gn/T/go-build916245002=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

1. Run gomobile build -target=ios -bundleid=com.hajimehoshi.gomobiletest -work golang.org/x/mobile/example/basic
2. Open the generated main.xcodeproj
3. Install it on a device (iPhone 6 in my case)
4. Run the app via Instruments memory profiler (Zombie)

What did you expect to see?

The app runs without memory increase.

What did you see instead?

The memory usage is increased monotonically:

It looks like _IOAccelResourceAlloc allocates memory and it is never disposed? I'm not sure this is an actual leak.