I have encountered an issue, which I may fix myself at some point, although for now I have no idea where it comes from.
I have a program, dem_adjust, in asp/srs/Tools. It depends on geographylib. Both this program and its depending library have include flags of the form:
The flag PKG_DEM_ADJUST_CPPFLAGS does not get passed dem_adjust when it is being built, as it should, that is bad. However, the flag PKG_GEOGRAPHICLIB_CPPFLAGS does gets passed to dem_adjust, since dem_adjust depends on this library.
So I used this workaround, but it it still somewhat annoying that a given flag specified for a given program does not get passed to it when building it.
Minor internal build thing I raised a while ago. Internal workaround works fine. Not worth bothering with.