can't go build on windows

[jiyilanzhou]

Describe the bug
when i build this project in my windows computor, build failed with undefined: syscall.Statfs_t

To Reproduce
Steps to reproduce the behavior:

1. Run '...'
2. See error

D:\goSpace\pkg\mod\github.com\filecoin-project\sector-storage@v0.0.0-20200625154333-98ef8e4ef246\stores\interface.go:41:11: undefined: syscall.Statfs_t
D:\goSpace\pkg\mod\github.com\filecoin-project\sector-storage@v0.0.0-20200625154333-98ef8e4ef246\stores\interface.go:42:12: undefined: syscall.Statfs
# pkg-config --cflags  -- D:/goSpace/src/github.com/filecoin-project/lotus/extern/filecoin-ffi/generated/../filcrypto.pc D:/goSpace/src/github.com/filecoin-project/lotus/extern/filecoin-ffi/generated/../filcrypto.pc D:/goSpace/src/github.com/filecoin-project/lotus/extern/filecoin-ffi/generated/../filcrypto.pc D:/goSpace/src/github.com/filecoin-project/lotus/extern/filecoin-ffi/generated/../filcrypto.pc D:/goSpace/src/github.com/filecoin-project/lotus/extern/filecoin-ffi/generated/../filcrypto.pc
pkg-config: exit status 3221225781

Expected behavior
build success

Screenshots
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Version (run lotus --version):

Additional context
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[RobQuistNL]

On windows the syscall.statfs (fetching the free diskspace) should probably be replaced with something like this;

h := syscall.MustLoadDLL("kernel32.dll")
c := h.MustFindProc("GetDiskFreeSpaceExW")

var freeBytes int64

_, _, err := c.Call(uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(wd))),
    uintptr(unsafe.Pointer(&freeBytes)), nil, nil)

Windows is not officially supported so it might take while for this to be fixed - and there will probably be many more errors when compiling on windows.

[Kubuxu]

The bigger problem will be the lack of filecoin-ffi for Windows.

[magik6k]

Duplicate of #2133