在brew upgrade的时候，出错信息如下：

brew upgrade
==> Upgrading 1 outdated package, with result:
go 1.5.1
==> Upgrading go
==> Downloading https://storage.googleapis.com/golang/go1.5.1.src.tar.gz
Already downloaded: /Library/Caches/Homebrew/go-1.5.1.tar.gz
==> Downloading https://storage.googleapis.com/golang/go1.4.2.darwin-amd64-osx10.8.tar.gz
Already downloaded: /Library/Caches/Homebrew/go--gobootstrap-10.8.tar.gz
==> ./make.bash --no-clean
==> ./make.bash --no-clean
==> Cloning https://go.googlesource.com/tools.git
Cloning into '/Library/Caches/Homebrew/go--gotools--git'...
fatal: unable to access 'https://go.googlesource.com/tools.git/': Failed to connect to go.googlesource.com port 443: Operation timed out
Error: Failed to download resource "go--gotools"
Failure while executing: git clone https://go.googlesource.com/tools.git /Library/Caches/Homebrew/go--gotools--git
于是我想到，可以使用proxychains4来进行访问（之前已经安装 goagentx + cow [with shadowsocks] ），然而： 
proxychains4 brew upgrade
[proxychains] config file found: /usr/local/Cellar/proxychains-ng/4.10/etc/proxychains.conf
[proxychains] preloading /usr/local/Cellar/proxychains-ng/4.10/lib/libproxychains4.dylib
==> Upgrading 1 outdated package, with result:
go 1.5.1
==> Upgrading go
==> Downloading https://storage.googleapis.com/golang/go1.5.1.src.tar.gz
Already downloaded: /Library/Caches/Homebrew/go-1.5.1.tar.gz
==> Downloading https://storage.googleapis.com/golang/go1.4.2.darwin-amd64-osx10.8.tar.gz
Already downloaded: /Library/Caches/Homebrew/go--gobootstrap-10.8.tar.gz
==> ./make.bash --no-clean
Last 15 lines from /Users/xiaojianliang/Library/Logs/Homebrew/go/01.make.bash:
text/template
go/doc
go/build
cmd/go
fatal error: runtime: bsdthread_register error (unset DYLD_INSERT_LIBRARIES)

runtime stack:
runtime.throw(0x3e9855)
/usr/local/go/src/runtime/panic.go:491 +0xad fp=0x7fff5fbff390 sp=0x7fff5fbff360
runtime.goenvs()
/usr/local/go/src/runtime/os_darwin.c:103 +0x60 fp=0x7fff5fbff3a8 sp=0x7fff5fbff390
runtime.schedinit()
/usr/local/go/src/runtime/proc.c:141 +0x5f fp=0x7fff5fbff3d0 sp=0x7fff5fbff3a8
runtime.rt0_go(0x7fff5fbff408, 0x4, 0x7fff5fbff408, 0x0, 0x0, 0x4, 0x7fff5fbff670, 0x7fff5fbff6c6, 0x7fff5fbff6cc, 0x7fff5fbff6cf, ...)
/usr/local/go/src/runtime/asm_amd64.s:95 +0x116 fp=0x7fff5fbff3d8 sp=0x7fff5fbff3d0

READ THIS: https://git.io/brew-troubleshooting

These open issues may also help:
Homebrew goes ahead with installation after warning dev tools aren't installed https://github.com/Homebrew/homebrew/issues/19580
这回倒好，还没有到git clone，就直接出错了。看来proxychains和golang不兼容，怎么办？于是干脆我直接先clone一下看看： 
:~$ proxychains4 git clone https://go.googlesource.com/tools.git /Library/Caches/Homebrew/go--gotools--git
[proxychains] config file found: /usr/local/Cellar/proxychains-ng/4.10/etc/proxychains.conf
[proxychains] preloading /usr/local/Cellar/proxychains-ng/4.10/lib/libproxychains4.dylib
Cloning into '/Library/Caches/Homebrew/go--gotools--git'...
remote: Counting objects: 827, done
remote: Finding sources: 100% (12/12)
remote: Total 14355 (delta 9764), reused 14348 (delta 9764)
Receiving objects: 100% (14355/14355), 8.98 MiB | 119.00 KiB/s, done.
Resolving deltas: 100% (9764/9764), done.
Checking connectivity... done.
果然OK了。那么我再直接试一下upgrade吧？ 
brew upgrade
==> Upgrading 1 outdated package, with result:
go 1.5.1
==> Upgrading go
==> Downloading https://storage.googleapis.com/golang/go1.5.1.src.tar.gz
Already downloaded: /Library/Caches/Homebrew/go-1.5.1.tar.gz
==> Downloading https://storage.googleapis.com/golang/go1.4.2.darwin-amd64-osx10.8.tar.gz
Already downloaded: /Library/Caches/Homebrew/go--gobootstrap-10.8.tar.gz
==> ./make.bash --no-clean
==> ./make.bash --no-clean
==> Cloning https://go.googlesource.com/tools.git
Updating /Library/Caches/Homebrew/go--gotools--git
==> Checking out revision d02228d1857b9f49cd0252788516ff5584266eb6
==> go build
==> go build
==> Caveats
As of go 1.2, a valid GOPATH is required to use the `go get` command:
https://golang.org/doc/code.html#GOPATH

You may wish to add the GOROOT-based install location to your PATH:
export PATH=$PATH:/usr/local/opt/go/libexec/bin
==> Summary