$ gomobile bind -target=android mobile1.go 
C:\Users\ding\go\bin\gomobile.exe: C:\Users\ding\go\bin\gobind.exe -lang=go,java -outdir=C:\Users\ding\AppData\Local\Temp\gomobile-work-767461627 command-line-arguments failed: exit status 1
no exported names in the package "command-line-arguments"
no exported names in the package "command-line-arguments"
no exported names in the package "command-line-arguments"
no exported names in the package "command-line-arguments"

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

$ go env
set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\ding\AppData\Local\go-build
set GOENV=C:\Users\ding\AppData\Roaming\go\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\ding\go
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=F:\Go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=F:\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\ding\AppData\Local\Temp\go-build194312410=/tmp/go-build -gno-record-gcc-switches