dev-python/uvicorn-0.34.0 with USE=test depends on >=dev-python/httptools-0.6.3[${PYTHON_USEDEP}] >=dev-python/httpx-0.28[${PYTHON_USEDEP}] while dev-python/httpx-0.28.1 hard-blocks !!dev-python/httptools[${PYTHON_USEDEP}] with USE=test. When no restriction on tests is manually set, dev-python/uvicorn-0.34.0 cannot be installed. Maybe you agree that this is not optimal and some more friendly solution can be achieved.
I know, and I hate it. Basically the problem is: 1. httptools mess things up and httpx tests fail because of that [1]. 2. uvicorn's test require httptools. It used to be optional, but upstream regularly breaks that and I've stopped caring to keep sending patches. Apparently [1] has a patch suggested, but upstream is kinda special and expects us to file a discussion first and wait weeks for a reply. [1] https://github.com/encode/httpx/discussions/3429