Build Constraints question

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1

I’ve been trying to implement Build Constraints while trying to build a modified version of grafana. All my attempts at setting the “-tags” build argument have been unsuccessful.

In the code below, package 1 will be for a production build, and package 2 is for development (much more logging is included.)

Version:

$ go version
go version go1.9.1 linux/amd64

Build:

go build -tags DEVTEST -ldflags -w -X main.version=4.7.0-pre1 main.commit=91f60bb -o ./bin/grafana-server ./pkg/cmd/grafana-server

package 1:

// +build !DEVTEST

package middleware

<package code here>

package 2:

// +build DEVTEST

package middleware

<package code here>

All my attempts have ended with all items in the package shown as redeclared, implying the build contraints were not applied.

Any insights?

Drew

2

Looks correct to me (apart from the ldflags argument lacking quotes). Maybe something is different in what you have or what you do than you are showing here?

(That is: please show your real code and real error.)

3

Ok, here is the actual console output:

go build -i --tags DEVTEST -ldflags -w -X main.version=4.7.0-pre1 -X main.commit=91f60bb -X main.buildstamp=1507907560 -o ./bin/grafana-server ./pkg/cmd/grafana-server
# github.com/grafana/grafana/pkg/middleware
pkg/middleware/middlewaredev.go:28:6: Context redeclared in this block
	previous declaration at pkg/middleware/middleware.go:28:6
pkg/middleware/middlewaredev.go:40:26: GetContextHandler redeclared in this block
	previous declaration at pkg/middleware/middleware.go:40:26
pkg/middleware/middlewaredev.go:160:49: initContextWithAnonymousUser redeclared in this block
	previous declaration at pkg/middleware/middleware.go:160:49
pkg/middleware/middlewaredev.go:181:66: initContextWithUserSessionCookie redeclared in this block
	previous declaration at pkg/middleware/middleware.go:181:66
pkg/middleware/middlewaredev.go:204:42: initContextWithApiKey redeclared in this block
	previous declaration at pkg/middleware/middleware.go:204:42
pkg/middleware/middlewaredev.go:240:58: initContextWithBasicAuth redeclared in this block
	previous declaration at pkg/middleware/middleware.go:240:58
pkg/middleware/middlewaredev.go:283:6: (*Context).Handle redeclared in this block
	previous declaration at pkg/middleware/middleware.go:283:6
pkg/middleware/middlewaredev.go:296:6: (*Context).JsonOK redeclared in this block
	previous declaration at pkg/middleware/middleware.go:296:6
pkg/middleware/middlewaredev.go:302:6: (*Context).IsApiRequest redeclared in this block
	previous declaration at pkg/middleware/middleware.go:302:6
pkg/middleware/middlewaredev.go:342:34: AddDefaultResponseHeaders redeclared in this block
	previous declaration at pkg/middleware/middleware.go:342:34
pkg/middleware/middlewaredev.go:302:6: too many errors

Source code has been placed on github at:

4

So I couldn’t see anything wrong, and even pulled down your repo to double check, and got the same issue as you despite everything looking fine. Then I noticed:

38
383104×2014 491 KB

The BOM is an extra two byte binary marker at the start of the file. It makes the compiler not see the build tag comment. Re-save as regular UTF-8 without BOM and you’re good.

1 Like
5

You sir, are VERY observant!! Your suggestion worked!

I owe you more than a beer, instead I’ll offer 1 mole of thank you’s (6.022 x 10E23).

1 Like