custom theme not installed

[uhrohraggy]

the default composer.json at the root has the path specified to include themes, and my theme has a composer similar to your example, but it's not getting installed, only the packagist ones are. Do i need to do anything aside from pushing to heroku?

running heroku run 'composer update' or install throws
ading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 27 installs, 25 updates, 1 removal

• Removing mustangostang/spyc (0.6.1)
• Updating johnpbloch/wordpress-core-installer (0.2.1 => 1.0.0): Downloading (100%)
• Updating composer/installers (v1.2.0 => v1.3.0):Downloading (100%) )
• Installing wp-cli/autoload-splitter (v0.1.3): Downloading (100%)

[InvalidArgumentException]
Two packages cannot share the same directory!

update [--prefer-source] [--prefer-dist] [--dry-run] [--dev] [--no-dev] [--lock] [--no-custom-installers] [--no-autoloader] [--no-scripts] [--no-progress] [--no-suggest] [--with-dependencies] [-v|vv|vvv|--verbose] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--apcu-autoloader] [--ignore-platform-reqs] [--prefer-stable] [--prefer-lowest] [-i|

[luizs81]

You can find the answer here
roots/bedrock#309