lang/rust PORT_LLVM=on Dependency loop detected

I tried to build our package set (in Poudriere) with the new option 
PORT_LLVM=on for lang/rust, but it seems it does not work / has not been 
tested, or we have some other non-default options that cause the 
following error:

[00:00:57] Error: Dependency loop detected:
These packages depend on each other: py39-openssl-23.2.0,1 
py39-cryptography-41.0.7_1,1 rust-1.74.1 llvm15-15.0.7_9 
py39-recommonmark-0.5.0_2 py39-sphinx-5.3.0_1,1 py39-requests-2.31.0 
py39-urllib3-1.26.18,1
These packages depend on each other: rust-1.74.1 llvm15-15.0.7_9 
py39-recommonmark-0.5.0_2 py39-sphinx-5.3.0_1,1 py39-requests-2.31.0 
py39-urllib3-1.26.18,1 py39-openssl-23.2.0,1 
py39-cryptography-41.0.7_1,1 py39-setuptools-rust-1.8.1

Is it supposed to work? How can I trace what port / option is pulling 
"bad dependency"?

Kind regards
Miroslav Lachman