How to deploy GoLang Binaries to CF

Hi we are trying to deploy golang binaries to cf.

for example main.exe which is in /deploy/ folder along with mainfest file

Note: It is also observed that if we push the whole project app then it works. but if we try to push only binaries then we get the below error

And Manifest file contains following info

 applications:
    - name: test-app
      command: test-app
      env:
        GO_INSTALL_PACKAGE_SPEC: ./



**ERROR** To use go native vendoring set the $GOPACKAGENAME
          environment variable to your app's package name
          **ERROR** Unable to determine import path: GOPACKAGENAME unset

After adding GOPACKAGENAME: main since main.exe is our binary name we get following error below

  Failed to compile droplet: Failed to run finalize script: exit status 12
   Cell 507b6e9c-c5c5-4685-9a71-d7cc1c876f5a stopping instance 6a92ff73-76ec-4baf-8a3e-54b54cfa307e
BuildpackCompileFailed - App staging failed in the buildpack compile phase

thanks @Volker for pointing out

for above issue:

first we have to build with following command (used make file)

GOOS="linux" go build main.go

then copy that main binary to /deploy folder

then manifest file in the deploy folder

applications:
    - name: test-app
      command: ./main
      stack: cflinuxfs3
      buildpacks:
        - https://github.com/cloudfoundry/binary-buildpack.git

Then to push to cf

cf push -f ./manifest-template.yml