Qt Creator appears to run qmake outside of the docker container for configuration and pro file scanning, despite the docker container showing a qmake process running.

As an example, I have a very simple docker container used to build auto test binaries:

FROM ubuntu:20.04
ARG DEBIAN_FRONTEND=noninteractive
# get dependencies
RUN apt-get update; \
    apt-get install --yes --no-install-recommends \
    build-essential \
    qt5-default \
    libgstreamer1.0-dev \
    libgstreamer-plugins-base1.0-dev \
    libudev-dev \
    qtdeclarative5-dev \
    libqt5serialport5-dev \
    qtpositioning5-dev

Using this docker container as a device, and creating a kit for it works fine when I build or run the project. However, right-clicking on the project in QtCreator and selecting "run qmake" fails to gstreamer-1.0 dev packages, which should be made available via libgstreamer1.0-dev. I have similar issues if I try to use a custom qmake spec which is added to the docker container - building the application works fine, but parsing the project file fails. This is a significant issue in this case because the project can't be loaded (no libraries, sources etc listed) when the qmake spec is missing.