"make daemon" doesn't build on Go 1.16 due to changes to its module system

[joeshaw]

Describe the bug

If you have Go 1.16 installed, the Go portions of the project no longer build. For example, make daemon. This is because Go 1.16 switched to requiring Go modules by default.

pronto /tmp/c-sdk (main)$ make daemon
/Applications/Xcode.app/Contents/Developer/usr/bin/make USE_SYSTEM_CERTS=1 -C vendor/newrelic daemon
go install -ldflags '-X newrelic/version.Number=1.3.0.0 -X newrelic/version.Commit=fe05ae84e4fe -X newrelic/secrets.NewrelicCollectorHost= -X newrelic/secrets.NewrelicLicenseKey= -X newrelic/secrets.NewrelicCollectorKeys=' -tags='use_system_certs' ./...
go: cannot find main module, but found .git/config in /private/tmp/c-sdk
	to create a module there, run:
	cd ../.. && go mod init
make[1]: *** [daemon] Error 1
make: *** [newrelic-daemon] Error 2

pronto /tmp/c-sdk (main)$ go version
go version go1.16.2 darwin/amd64

Your Environment

I'm running this on MacOS 11.3 (Big Sur) with Go 1.16.2, but this also happens on Linux.

Additional context

A summary of the modules changes is available on the Go blog: https://blog.golang.org/go116-module-changes

A temporary workaround is to set GO111MODULES=auto. However, non-modules (aka GOPATH-mode) is scheduled to be dropped in Go 1.17.

The build system of Go code in this repository is very unusual, and doesn't follow best practices. For example, overriding GOPATH and not namespacing package import paths. One of the reason why projects did this, however, is because GOPATH was global on a user's machine. The Go module system makes this a lot cleaner and allows you to specify your dependencies more exactly.

My suggestion is to bump the minimum required Go version to 1.13 (the first one where modules were enabled and auto-detected) and switch to using Go modules. Go 1.13 was released in September 2019.

[ralvescosta]

I can't compile the daemon, I got the same error. I'm tried using go 1.16.7 and 1.17.1 and in both, I received the same error.

[zsistla]

Hi @ralvecosta,

Sorry to hear about the error.

Starting with g 1.16, go requires use of modules by default.

From the release notes:

Note that Go 1.16 requires use of Go modules by default, now that, according to our 2020 Go Developer Survey, 96% of Go developers have made the switch. We recently added official documentation for developing and publishing modules.

However, in the release notes(and thanks to @joeshaw for also providing the details), they also documented how to change the default.

Modules

Module-aware mode is enabled by default, regardless of whether a go.mod file is present in the current working directory or a parent directory. More precisely, the GO111MODULE environment variable now defaults to on. To switch to the previous behavior, set GO111MODULE to auto.

This can be accomplished in a variety of ways. 2 of those ways are:

1. Add export GO111MODULE=auto to the .bashrc file
   OR
2. From the system prompt, type export GO111MODULE=auto && go1.16 env GO111MODULE auto

@ralvescosta please let us know if one of the above solves the issue for you.

Unfortunately, for backwards compatibility purposes, we still support a very old version of go and so are not quite able to move forward to current best practices as recommended by @joeshaw