Dockerfile: add GOTOOLCHAIN

[hdonnay]

Changes in go1.21 means the build recipe here was doing the wrong thing. This should restore the expected behavior of using the toolchain present in the container.

[hdonnay]

Cc: @bcaton85

[bcaton85]

I still get the same (go: no modules specified (see 'go help mod download'))

[hdonnay]

Using what command line?

[bcaton85]

this is ran in a bash shell, if i'm understanding your question correctly

[hdonnay]

No, what's the command you're using to build the container?

[bcaton85]

just podman build .

[hdonnay]

Can't reproduce, works on Fedora 40

[bcaton85]

Yeah i'm on mac, maybe it's a mac issue. TBF i don't think this is a big deal if it doesn't effect development

[hdonnay]

This works with "normal" podman but not podman-remote due to SELinux shenanigans:
The go: no modules specified error is reported when there's not a module in the specified directory, but also ends up getting reported when SELinux denies any access to the go.mod file and its metadata.
Adding the relabel flag would make this work uniformly under podman and podman-remote, but is not accepted (AFAICT) by Docker/Moby/BuildKit.

@crozzy This is probably good to go.

[hdonnay]

/fast-forward