go buildを実行しているパッケージが見つかりません。

root@kali:~/subfinder# go build
main.go:15:2: cannot find package 
"github.com/subfinder/subfinder/libsubfinder/helper" in any of:
    /usr/lib/go-1.11/src/github.com/subfinder/subfinder/libsubfinder/helper 
(from $GOROOT)
    /root/go
/src/github.com/subfinder/subfinder/libsubfinder/helper (from $GOPATH)
main.go:16:2: cannot find package "github.com/subfinder/subfinder/subf" in 
any of:
    /usr/lib/go-1.11/src/github.com/subfinder/subfinder/subf (from $GOROOT)
    /root/go
/src/github.com/subfinder/subfinder/subf (from $GOPATH)

私のバージョンのパスは次のとおりです。

root@kali:~# go version
go version go1.11.4 linux/386

My Go環境：

root@kali:~# go env
GOARCH="386"
GOBIN="/root/go_projects/bin"
GOCACHE="/root/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="386"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/root/go
"
GOPROXY=""
GORACE=""
GOROOT="/usr/lib/go-1.11"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go-1.11/pkg/tool/linux_386"
GCCGO="gccgo"
GO386="387"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m32 -pthread -fmessage-length=0 -fdebug-prefix- 
map=/tmp/go- 
build284184378=/tmp/go-build -gno-record-gcc-switches"

私の履歴書

# ~/.profile: executed by Bourne-compatible login shells.

if [ "$BASH" ]; then
      if [ -f ~/.bashrc ]; then
    . ~/.bashrc
 fi
 fi

 mesg n || true

export PATH=$PATH:/usr/local/go/bin
export GOPATH="$HOME/go_projects"
export GOBIN="$GOPATH/bin"