[PyQt] PyQt 5.13.2 build error: module 'sipbuild.api' has no attribute ‘prepare_metadata_for_build_wheel'

[FX]

Dear Phil,

> You are trying to deal with two significant changes (PyQt v5.11 and SIP v5) at the same time. I'd suggest you start by building PyQt v5.13.2 with SIP v4.19.19.

Indeed. Building PyQt v5.13.2 with SIP v4.19.19 turned out to be easy, and we have merged that. I am now focussing on updating to SIP 5.0.0, and making sure PyQt 5.13.2 builds with SIP 5.0.0.

1. SIP 5.0.0 installs easily from sdist with pip, as stated in the documentation
2. I see in the PyQt doc that our build method (based on configure.py) needs to be changed to use sip-install. So I try this. But:
3. I am trying to build pyqt with:

sip-install --target-dir=/usr/local/Cella/pyqt/5.13.2/lib/python37/site-packages

and the documentation of --target-dir says "The project will be installed in DIR.”
Yet sip-install tries to copy files into directory outside of DIR, namely, in /usr/local/Cellar/sip/5.0.0/libexec/bin

I am unsure if this is a bug (it contradicts the documentation) or a feature. As I said in an earlier email, when building PyQt with configure.py, there is an option (--bindir) that decides where these files would be installed. I cannot, however, find a similar option for sip-install.

Thanks,
FX