Wednesday, 30 December 2020

Microsoft Visual Studio Code and Go - compiler says "No" - "main redeclared in this block" -

 So I had a bit of a face-palm moment this afternoon, whilst discussing how to configure Microsoft Visual Studio Code ( aka VS Code ) with Go on macOS 11 Big Sur.

Having updated Go to the most recent version: -

go version

go version go1.15.6 darwin/amd64

I was trying/failing to run a newly created Hello World Go module within VS Code itself: -


package main

import "fmt"

func main() {

fmt.Printf("hello, world\n")


However, VS Code just returns: -

# hello
/Users/hayd/go/src/hello/hello.go:5:6: main redeclared in this block
previous declaration at /Users/hayd/go/src/hello/hello-world.go:5:6
Build process exiting with code: 2 signal: null

within the Debug Console and, within the Problems perspective, I see: -

Now it **SHOULD** be obvious .....

But I'm obviously getting old ....

Can you see what I'm doing wrong ? I bet you can ....

Having validated that the module ran OK from the Terminal: -

cd $GOPATH/src/hello

go run hello-world.go 

hello, world

I again missed the obvious: -

ls -al

total 16
drwxr-xr-x  5 hayd  staff  160 30 Dec 17:27 .
drwxr-xr-x  9 hayd  staff  288 11 Sep 10:50 ..
-rw-r--r--  1 hayd  staff   74 30 Dec 17:27 hello-world.go
-rw-r--r--  1 hayd  staff   74 20 Feb  2020 hello.go
drwxr-xr-x  2 hayd  staff   64 20 Feb  2020 vendor

cat hello.go

package main

import "fmt"

func main() {
fmt.Printf("hello, world\n")

cat hello-world.go

package main

import "fmt"

func main() {
fmt.Printf("hello, world\n")

To put you, and me, out of our collective miseries, my mistake was ....


Exactly as the VS Code errors were telling me: -

other declaration of main

main redeclared in this block

Yep, once I nuked the second instance: -

rm hello-world.go

VS Code was happy: -

and the remaining hello.go module ran happily: -

Can you say "Doofus" ? I bet you can ......

No comments:

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