go: fix installation of external tools with Go 1.7

[rasky]

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---

Go 1.7 integrated go vet in the standard toolchain, so it's not part of the external tools repo anymore. This PR fixes two related bugs in the formula:

• Make sure that we checkout the correct tools branch when building devel; previously, it would always build the branch of the stable version. This is a potential bug because you can't use old tools (aligned with a previous version) with a newer Go version and expect them to work. See for instance go 1.7beta1: go vet: import failed: fmt.a:1:4 (byte offset = 3): expected keyword package, got "cn" golang/go#16044 (that is fixed by this patch).
• Add a workaround to avoid failing when trying to install go vet from the tools directory. Once Go 1.7 is released and the whole formula cleaned up, the whole codeblock can just be removed.

[DomT4]

I'm not sure this is working as intended. It's building the 1.7 branch even for brew install go (i.e. the stable spec):

==> Cloning https://go.googlesource.com/tools.git
git clone --branch release-branch.go1.7 https://go.googlesource.com/tools.git /usr/local/var/homebrew/cache/go--gotools--git
Cloning into '/usr/local/var/homebrew/cache/go--gotools--git'...
remote: Sending approximately 11.37 MiB ...
remote: Counting objects: 770, done
remote: Finding sources: 100% (10/10)
remote: Total 16308 (delta 11045), reused 16303 (delta 11045)
Receiving objects: 100% (16308/16308), 11.34 MiB | 7.16 MiB/s, done.
Resolving deltas: 100% (11045/11045), done.
Checking connectivity... done.
git config homebrew.cacheversion 0
==> Checking out branch release-branch.go1.7
git checkout -f release-branch.go1.7 --
Already on 'release-branch.go1.7'
Your branch is up-to-date with 'origin/release-branch.go1.7'.

[rasky]

Oops thanks for noticing.

Any advice on how to fix it? How can I checkout different branches depending on whether the user requested the stable or devel version?

Giovanni Bajo
Develer S.r.l.
http://www.develer.com
Sent from mobile

Il giorno 10 lug 2016, alle ore 14:21, Dominyk Tiller notifications@github.com ha scritto:

I'm not sure this is working as intended. It's building the 1.7 branch even for brew install go (i.e. the stable spec):

==> Cloning https://go.googlesource.com/tools.git
git clone --branch release-branch.go1.7 https://go.googlesource.com/tools.git /usr/local/var/homebrew/cache/go--gotools--git
Cloning into '/usr/local/var/homebrew/cache/go--gotools--git'...
remote: Sending approximately 11.37 MiB ...
remote: Counting objects: 770, done
remote: Finding sources: 100% (10/10)
remote: Total 16308 (delta 11045), reused 16303 (delta 11045)
Receiving objects: 100% (16308/16308), 11.34 MiB | 7.16 MiB/s, done.
Resolving deltas: 100% (11045/11045), done.
Checking connectivity... done.
git config homebrew.cacheversion 0
==> Checking out branch release-branch.go1.7
git checkout -f release-branch.go1.7 --
Already on 'release-branch.go1.7'
Your branch is up-to-date with 'origin/release-branch.go1.7'.
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[DomT4]

Oops thanks for noticing

'Tis why I'm here 😉.

It should just be a case of moving the resource inside respective stable do & devel do blocks with go_version set there. Will check it out more later today.

[DomT4]

Pushed some extra changes to this myself afterwards in ac2b85f, but merged your commit in 0e12b73. Apologies for the slow review here, things have been hectic lately. Appreciate your contribution to Homebrew 🙇