I'm trying to create an unattended (and perhaps deterministic) build process for an application written in Go.
The idea is to use create a Dockerfile which installs all the prerequisites so it's easy to share the build process with others and doesn't require a real windows installation.
However I'm stuck trying to build a library that has C bindings.
I get this very non-descriptive error
C:\godev\src\github.com\obscuren\secp256k1-go>go build --work
WORK=C:\usersoot\Temp\go-build287695705
# _/C_/godev/src/github.com/obscuren/secp256k1-go
copying $WORK\_\C_\godev\src\github.com\obscuren\secp256k1-go\_obj\_cgo_defun.8 to $WORK\_\C_\godev\src\github.com\obscuren\secp256k1-go.a: write $WORK\_\C_\godev\src\github.com\obscuren\secp256k1-go.a: Access denied.
A full log with -x can be found here.
I can build this library on OS X and a 'real' Windows installation just fine.
Any help would be appreciated.
Edit:
Using the outline by OneofOne also gives me some errors.
# runtime/cgo
pkg/runtime/cgo/cgo.go:26:46: fatal error: sys/types.h: No such file or directory.
compilation terminated.
Initially I got this error when enabling cross-compiling for Go. I overcame that by installing gcc-multilib. The next problem is the following.
# runtime/cgo
gcc: error: unrecognized command line option ‘-mthreads’
Googling for this error results in two hits which are not useful to my user-case. I'm hoping anybody experienced this before.
Edit 2:
Not sure yet what solved it but I did
apt-get install gcc-multilib
apt-get install gcc-mingw-w64
And used
GOOS=windows GOARCH=386 CGO_ENABLED=1 CXX_FOR_TARGET=i686-w64-mingw32-g++ CC_FOR_TARGET=i686-w64-mingw32-gcc ./make.bash
Now I'm a step further. :)
While not an answer to the exact question, the proper way of doing this is using mingw64 on Linux to cross-compile windows executables, I've used it several times in my projects and it worked fine.
First, you have to enable crosscompiling in Go:
┌─ oneofone@Oa [~]
└──➜ cd $GOROOT/src
┌─ oneofone@Oa [/u/s/g/src]
└──➜ env GOOS=windows GOARCH=386 CGO_ENABLED=1 ./make.bash #use GOARCH=amd64 for 64bit windows binaries
....compile progress...
┌─ oneofone@Oa [/u/s/g/src]
└──➜ cd /tmp
┌─ oneofone@Oa [/tmp]
└──➜ cat win-cgo-test.go
package main
/*
#include <stdlib.h>
#include <stdio.h>
*/
import "C"
import "unsafe"
func main() {
hello := C.CString("Hello world")
defer C.free(unsafe.Pointer(hello))
C.puts(hello)
}
Then install the mingw toolchain, on Arch Linux:
Add this to /etc/pacman.conf:
[mingw-w64]
SigLevel = Never
Server = http://downloads.sourceforge.net/project/mingw-w64-archlinux/$arch
Server = http://arch.linuxx.org/archlinux/$repo/os/$arch
then run pacman -Syu mingw-w64-toolchain mingw-w64
Edit: also if you are on a 64bit distro you need multilib gcc, on ArchLinux that's usually pacman -Sy multilib-devel
.
Depends on your distro, there's usually either a native repo or someone made a custom repo for mingw.
After it all installs, you can compile your windows executables by running:
┌─ oneofone@Oa [/tmp]
└──➜ env GOOS=windows GOARCH=386 CGO_ENABLED=1 CC=i686-w64-mingw32-gcc CXX=i686-w64-mingw32-g++ CGO_LDFLAGS="-lssp" go build win-cgo-test.go
┌─ oneofone@Oa [/tmp]
└──➜ file win-cgo-test.exe
win-cgo-test.exe: PE32 executable (console) Intel 80386 (stripped to external PDB), for MS Windows
I have them as aliases in my shell, https://github.com/OneOfOne/etc-fish/blob/master/env/01-go.fish.
I use Fish, however they are simple enough to port to Bash (or anything else really).
//edit, a bonus
If you want to get a list of the required dlls (99% of the time you don't need to copy anything, but just for the 1%):
└──➜ i686-w64-mingw32-objdump -p win-cgo-test.exe | grep "DLL Name:"
DLL Name: ws2_32.dll
DLL Name: advapi32.dll
DLL Name: ntdll.dll
DLL Name: kernel32.dll
DLL Name: winmm.dll
DLL Name: msvcrt.dll