无法编译Go文件-“初始化失败…在此块中重新声明了xxxx”

Question

I am new in Go and I follow the instructions in the website and the youtube video I am getting the follow errors when I run go build hello.go:

go: disabling cache (/home/myuser/.cache/go-build) due to initialization failure: open /home/myuser/.cache/go-build/log.txt: permission denied
# runtime
/usr/local/go/src/runtime/map.go:64:2: bucketCntBits redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:64:18
/usr/local/go/src/runtime/map.go:65:2: bucketCnt redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:65:23
/usr/local/go/src/runtime/map.go:69:2: loadFactorNum redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:69:18
/usr/local/go/src/runtime/map.go:70:2: loadFactorDen redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:70:18
/usr/local/go/src/runtime/map.go:76:2: maxKeySize redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:76:17
/usr/local/go/src/runtime/map.go:77:2: maxValueSize redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:77:17
/usr/local/go/src/runtime/map.go:82:2: dataOffset redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:85:4
/usr/local/go/src/runtime/map.go:91:2: empty redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:91:19
/usr/local/go/src/runtime/map.go:92:2: evacuatedEmpty redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:92:19
/usr/local/go/src/runtime/map.go:93:2: evacuatedX redeclared in this block
    previous declaration at /usr/local/go/src/runtime/hashmap.go:93:19
/usr/local/go/src/runtime/map.go:93:2: too many errors

It wrote permission denied but I tried to run it with sudo go build and it also failed with:

sudo: go: command not found

I am working on Ubuntu 16.4. My go file hello.go is in $HOME/Desktop/go/src/hello.

My file $HOME/myuser/.profile contains:
PATH="$HOME/bin:$HOME/.local/bin:$PATH:/usr/local/go/bin"

Answer 1

Gopath

The GOPATH environment variable lists places to look for Go code.
On Unix, the value is a colon-separated string. On Windows, the value 
is a semicolon-separated string. On Plan 9, the value is a list.

GOPATH must be set to get, build and install packages outside the standard Go tree.
Use tool like dep to segregate your different go project, maintaining your project dependencies. 

Goroot

 The Go binary distributions assume they will be installed in /usr/local/go (or c:\Go under Windows), but it is possible to install 
the Go tools to a different location. In this case you must set the 
GOROOT environment variable to point to the directory in which it was installed.

so its always preferred to make your own gopath for compiling your code. GOPATH is for your own go projects / 3rd party libraries (downloaded with "go get").