Build fails on OpenBSD/arm(6)

[adowair]

Describe the bug
Cross-compiling the disk utility on openbsd/arm fails with the following error:

# github.com/shirou/gopsutil/disk
../../go/pkg/mod/github.com/shirou/gopsutil@v3.21.11+incompatible/disk/disk_openbsd.go:81:39: undefined: sizeOfDiskstats
../../go/pkg/mod/github.com/shirou/gopsutil@v3.21.11+incompatible/disk/disk_openbsd.go:85:14: undefined: sizeOfDiskstats
../../go/pkg/mod/github.com/shirou/gopsutil@v3.21.11+incompatible/disk/disk_openbsd.go:111:34: undefined: Diskstats
../../go/pkg/mod/github.com/shirou/gopsutil@v3.21.11+incompatible/disk/disk_openbsd.go:112:9: undefined: Diskstats

To Reproduce
Using Go v1.17.6, running:

GOOS=openbsd GOARCH=arm go build .

Expected behavior
The package should compile correctly =D

Environment (please complete the following information):

• Windows: [paste the result of ver]
• Linux: [paste contents of /etc/os-release and the result of uname -a]
• Mac OS: [paste the result of sw_vers and uname -a
• FreeBSD: [paste the result of freebsd-version -k -r -u and uname -a]
• OpenBSD: [paste the result of uname -a]

Additional context
I am cross-compiling on macOS Monterey (v12.0.1), with the following env:

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/ali.dowair/Library/Caches/go-build"
GOENV="/Users/ali.dowair/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/ali.dowair/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/ali.dowair/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.17.6/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.17.6/libexec/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17.6"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/ali.dowair/dev/kopia/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/pz/vhp6gb9900x1hw1cmkcn74s40000gp/T/go-build2010082161=/tmp/go-build -gno-record-gcc-switches -fno-common"

I see that this issue has come up before (#912, #1082), and wonder if the fixes for these are unstable, or if I'm doing something wrong. Looking at the package in this current version, I can see disk/types_openbsd.go, but it is hidden by the build tag ignore. Why is that?

[shirou]

We have arm64 definition but no arm. We would be very grateful if you could open a PR about the definition of arm.

[Lomanic]

Fixed with #1286