emerge of dev-cpp/glibmm-2.27.97 breaks with following error: The required module mm-common-util could not be found on this system. If you are running a binary distribution and the mm-common package is installed, make sure that any separate development package for mm-common is installed as well. If you built mm-common yourself, it may be necessary to adjust the PKG_CONFIG_PATH environment variable for pkg-config to find it. Always reproducible.
i can confirm this bug too
Please attach full build.log
Created attachment 266295 [details] build.log
i can also confirm this
confirmed!
Just ran into this bug, I was about to create a new one, but fortunately for the wranglers, I searched a bit before :-) I confirm this.
I added dev-cpp/mm-common to both gtkmm and glibmm. Please test and close this bug if it works.