Composer.json creates error

[bmoex]

In 6.2 the composer.json crashes the backend tool on dependency check.
#1382276561: The package "coreapi" depends on "lw/typo3cms-installers" which is not present in the system.

This is caused due to the unknown lw/typo3cms-installers. Why don't you use composer core installers?

You can than manually locate it where you want.

"require": {
"composer/installers": "~1.0"
},

with
"type": "typo3-cms-extension",

See https://github.com/composer/installers

If this is used, the 6.2 environment will be correctly handle the package.

[bmoex]

Will create a pull request

[etobi]

I'm sorry for any inconvenience. Thanks for reporting!
I tested it only it in an 6.1 environment, which uses the installer created by lightwerk (http://composer.lightwerk.com)

[bmoex]

Thanks for merging!