We need a way to push unstable snapshot packages to production online so that possible errors there won't affect other parts of the install-tree, so that the user can continue using the installer.
Now the installer will bail out if there is even one error anywhere in the install-tree.
e.g. in qt.59/package.xml
Then any error under "qt.59" would not tamper using the rest of the install-tree.
|For Gerrit Dashboard: QTIFW-930|
|221752,8||Add attribute to mark parts of install tree unstable||master||installer-framework/installer-framework||Status: MERGED||-2||0|