Go Heroku教程：无此类文件或目录：runtime.h

I'm working on the Golang Heroku tutorial right now, and I'm at this step: https://devcenter.heroku.com/articles/getting-started-with-go#prepare-the-app

When I execute the following:

go get github.com/heroku/go-getting-started/cmd/...

I get this error:

# runtime/cgo
/tmp/go-build867338420/runtime/cgo/_obj/_cgo_defun.c:4 6c: No such file or directory: runtime.h

Here is my go environment:

    GOARCH="amd64"
    GOBIN=""
    GOCHAR="6"
    GOEXE=""
    GOHOSTARCH="amd64"
    GOHOSTOS="linux"
    GOOS="linux"
    GOPATH="/home/crystal/go/"
    GORACE=""
    GOROOT="/usr/lib/go"
    GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
    TERM="dumb"
    CC="gcc"
    GOGCCFLAGS="-g -O2 -fPIC -m64 -pthread"
    CXX="g++"
    CGO_ENABLED="1"

What could potentially be the issue here?