doctrine/phpcr-odm — comment on commit 8cb85b10cc603a5ebad7f95f43a839754caa844f
File: composer.json line 16
By stof:

@dbu an implementation cannot reference a custom fork, except if this fork is registered on packagist with a different package name (which means it is not the same package for constraints and this is highly discouraged as it would require maintaining the fork once you publish it). Only the root composer.json file can specify custom repositories to use packages from another source