Upgrading Magento 2.2.6 to 2.3.0: Component Dependency

Question

Is there any way to upgrade from Magento 2.2.6 to 2.3 using the Web Setup Wizard? I'm getting the following error:

Check Component Dependency
We found conflicting component dependencies. Hide detail

Command "update" failed: Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

Problem 1
- Installation request for magento/product-community-edition 2.3.0 -> satisfiable by magento/product-community-edition[2.3.0].
- magento/module-wishlist-sample-data 100.2.0 requires magento/module-wishlist 101.0.* -> satisfiable by magento/module-wishlist[101.0.0, 101.0.1, 101.0.2, 101.0.3, 101.0.4, 101.0.5].
- Can only install one of: magento/module-wishlist[101.1.0, 101.0.0].
- Can only install one of: magento/module-wishlist[101.1.0, 101.0.1].
- Can only install one of: magento/module-wishlist[101.1.0, 101.0.2].
- Can only install one of: magento/module-wishlist[101.1.0, 101.0.3].
- Can only install one of: magento/module-wishlist[101.1.0, 101.0.4].
- Can only install one of: magento/module-wishlist[101.1.0, 101.0.5].
- magento/product-community-edition 2.3.0 requires magento/module-wishlist 101.1.0 -> satisfiable by magento/module-wishlist[101.1.0].
- Installation request for magento/module-wishlist-sample-data 100.2.* -> satisfiable by magento/module-wishlist-sample-data[100.2.0].

Please see screenshot:

My PHP version is 7.1.18 on CentOS 7, no Composer.

Answer 1

The Web Setup Wizard still uses Composer to do the upgrade, and the same changes are necessary before running a Wizard upgrade as they are a Command Line upgrade; the answer to Cannot upgrade from 2.2.6 to 2.3 via composer also applies here.