Binary distribution of a package using plugins

[Julio-Guerra]

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

$ go version
go version go1.12 linux/amd64

Does this issue reproduce with the latest release?

Yes.

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

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/julio/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/julio/go"
GOPROXY=""
GORACE=""
GOROOT="/home/julio/sdk/go1.12"
GOTMPDIR=""
GOTOOLDIR="/home/julio/sdk/go1.12/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-build607805819=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I would like to distribute some cgo bindings to a C++ library as a pre-compiled binary package in order to avoid asking users of this package to enable cgo and install gcc.
So I ended up on #28152 which says to use the Go plugins to do so. But now that I have my plugin wrapping the cgo bindings, I discover through my failing tests and in #28983 (comment) that "you have to build the plugin with the same dependencies as the binary".

I am unsure of what is exactly checked, but in this given use-case, the plugin cannot be built with the same packages as the binary that will load it. This binary is unknown in my case and I wanted to use the plugins as a way to load my package with cgo into any Go binary.

So this is very unexpected given the "plugin" name, and I am back to my starting point, for now giving up with plugins and rather document what it takes to use cgo because of my package.

Note that I also tried to find a way to simply use -buildmode archive and simply pass the compiled archive to go build or install without success.

[ianlancetaylor]

I think that everything you say in true. You can only use a plugin with the exact same Go release. Yes, this is a serious limitation on plugins, but there are no current plans to expand them. Sorry.

I'm going to close this issue because I don't really see any action we can take. Please comment if you disagree. You may also want to discuss this on a forum; see https://golang.org/wiki/Questions.

[Julio-Guerra]

You can only use a plugin with the exact same Go release.

@iamoryanmoshe It's even stronger than this: the compiled dependencies needs to be the same, and this seems to be enforced by checking the import paths in the importcfg.

(PS: no one answered me on golang-nuts ;-))