x/term: Fails to build with golang < 1.12

[aclindsa]

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

$ go version
go version go1.11.13 linux/amd64

Does this issue reproduce with the latest release?

It fails with the latest release of x/term and an older version of the go compiler, but not with the latest of both.

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

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/travis/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/travis/gopath"
GOPROXY=""
GORACE=""
GOROOT="/home/travis/.gimme/versions/go1.11.13.linux.amd64"
GOTMPDIR=""
GOTOOLDIR="/home/travis/.gimme/versions/go1.11.13.linux.amd64/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build186938083=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Attempted to build ofxgo on travis using go 1.11.

What did you expect to see?

golang.org/x/term

What did you see instead?

golang.org/x/term
# golang.org/x/term
../../../golang.org/x/term/term_unix_linux.go:9:7: ioctlReadTermios redeclared in this block
	previous declaration at ../../../golang.org/x/term/term_unix_aix.go:9:26
../../../golang.org/x/term/term_unix_linux.go:10:7: ioctlWriteTermios redeclared in this block
	previous declaration at ../../../golang.org/x/term/term_unix_aix.go:10:27

https://travis-ci.com/github/aclindsa/ofxgo/jobs/441671582

[FiloSottile]

Go 1.11 is not supported anymore (the earliest supported version is Go 1.14 at the moment), so it's to be expected that new versions of some modules will not build with it. (In this case, I think it's because Go 1.11 does not recognize the aix build tag.)

Due to how Minimum Version Selection works, the version of a dependency in use by a module is stable and will never update itself: you can continue to build the same code with an old version of the compiler forever. However, if you want to update a dependency you need to be prepared to update the compiler as well.

In general, Go 1.11 is lacking multiple security fixes that have been published over the last year, so I can't recommend running Go 1.11 at all. Remember that Go provides a strong backwards compatibility promise in order to make updates easier.