pack with Heroku static buildpack

gistfile1.txt

$ pack build react-pack --builder=heroku/buildpacks --buildpack https://cnb-shim.herokuapp.com/v1/heroku-community/static
latest: Pulling from heroku/buildpacks
Digest: sha256:14c60798f3cf5bcbab867213add52d134af3aaad3064062cafb25177cd48f5ed
Status: Image is up to date for heroku/buildpacks:latest
18: Pulling from heroku/pack
Digest: sha256:a3cb71855f7e399ad079f6f0fa5feb6cc93446a332d9b8ef535ca9a17dac92cf
Status: Image is up to date for heroku/pack:18
Downloading from https://cnb-shim.herokuapp.com/v1/heroku-community/static
3.35 MB/3.35 MB
===> DETECTING
[detector] heroku-community/static 0.1
===> ANALYZING
[analyzer] Warning: Image "index.docker.io/library/react-pack:latest" not found
===> RESTORING
===> BUILDING
[builder]   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
[builder]                                  Dload  Upload   Total   Spent    Left  Speed
100  838k  100  838k    0     0   769k      0  0:00:01  0:00:01 --:--:--  769k
[builder] -----> Installed directory to /app/bin
===> EXPORTING
[exporter] Adding layer 'launcher'
[exporter] Adding 1/1 app layer(s)
[exporter] Adding layer 'config'
[exporter] *** Images (83de14c64a1d):
[exporter]       index.docker.io/library/react-pack:latest
[exporter] Adding cache layer 'heroku-community/static:shim'
Successfully built image react-pack
Execution time: 48 s.