Multiple ports that depend on graphics/openjpeg cannot be built if both graphics/openjpeg and graphics/openjpeg15 are installed.
The header openjpeg.h is installed to /usr/local/include/openjpeg-2.3 by graphics/openjpeg, but the header with the same name is installed to /usr/local/include by graphics/openjpeg15. When a port is building, both /usr/local/include/openjpeg-2.3 and /usr/local/include are configured as include directories, so the port dependent on graphics/openjpeg tries to include /usr/local/include/openjpeg.h and then fails to build.
Example of such port: graphics/simpleviewer.
Moreover, if a port needs devel/doxygen and graphics/openjpeg in the same time - it cannot be built at all as devel/doxygen (indirectly) depends on graphics/openjpeg15, so graphics/openjpeg15 will be installed before the port and breaks the build.
The port graphics/openjpeg15 must install the header openjpeg.h into /usr/local/include/openjpeg-1.5 and change his pc file accordingly to avoid such conflicts.
will this ever be addressed or will be forced to start using custom ports trees?
see PR 262008
Overcomes by events
openjpeg15 installs include into own subdir since f3ba77e14cac05d43caf35100848eeaee3bc64b4