There is a relatively well known issue with compiling "large" qrc resources (i.e. 10-100MB, not really that large circa 2016). It's been reported before in QTBUG-50468,
QTBUG-55293, and QTBUG-54357, and the canonical solution is to add `CONFIG += big_resources` to the .pro file, which (from what I understand) enables a two-pass rcc which uses significantly less memory and is less likely to fail heap allocation.
However, this doesn't help the awesome part of the Qt user base who use CMake as their primary build system. There is no .pro file to add the "CONFIG" option to, nor (as far as I can tell), a way to use CMake to pass those options to anything which could make use of them. Additionally, there doesn't seem to be any mention of a two pass rcc in the CMake scripts anywhere, or any other way to enable it.
Can you please allow whatever functionality "CONFIG += big_resources" enables to be accessible through the CMake build system as well?