mac下打patch后编译安装golang

因为业务上的需求，架构师改了hack了一下golang的源码，放出一个patch文件，给源码打了patch之后，需要重新编译go源码，
我是用brew安装的golang, 先用go env看看

➜  ~ go env
GOARCH="amd64"
GOBIN="/Users/mac/go/bin"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/mac/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.7.5/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.7.5/libexec/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/w6/jggc8dbd719568_t2lfr2lbh0000gn/T/go-build024499459=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

锁定了源码的路径：/usr/local/Cellar/go/1.7.5/libexec

➜  ~ cd /usr/local/Cellar/go/1.7.5/libexec
➜  libexec ls
CONTRIBUTING.md PATENTS         api             doc             goid.patch      misc            robots.txt      test
CONTRIBUTORS    VERSION         bin             favicon.ico     lib             pkg             src
➜  libexec cd src
➜  src ./all.bash
##### Building Go bootstrap tool.
cmd/dist
ERROR: Cannot find /Users/mac/go1.4/bin/go.
Set $GOROOT_BOOTSTRAP to a working Go tree >= Go 1.4.

Go从1.5版本开始实现“自举”（Bootstrap），也就是用Go来实现Go、用Go来编译Go，因此这里的意思是系统默认用go1.4来编译golang，
但是我的系统里面并没有go1.4，这里偷个懒

➜  cp -r /usr/local/Cellar/go/1.7.5/libexec  /Users/mac/go1.4
➜  cd /usr/local/Cellar/go/1.7.5/libexec/src 
➜  src ./all.bash
##### Building Go bootstrap tool.
cmd/dist

##### Building Go toolchain using /Users/mac/go1.4.
bootstrap/internal/sys
bootstrap/compile/internal/big
bootstrap/internal/bio
bootstrap/asm/internal/flags
bootstrap/internal/obj
bootstrap/internal/gcprog
bootstrap/internal/obj/arm
bootstrap/internal/obj/arm64
...

等待编译测试完成即可。