Configuring Qt for the raspberry pi in 5.12.0 used to successfully compile:
and enable the associated functionality. This config test is not even touched in Qt 5.12.1
now barfs with:
Trying source 0 (type inline) of library bcm_host ...
None of [libbcm_host.so libbcm_host.a] found in  and global paths.
=> source produced no result.
Which makes sense as bcm_host lives in a discrete noncentral path, and we used to allow mkspecs to provide arbitrary link magic.
This is clearly not isolated to the egl-brcm config.test and must be giving anyone who tracks Qt patch releases (something I used to advocate) a really bad day.