Gwyddion ./configure detects the presence of openexr and, if present, compiles and installs a module /usr/lib64/gwyddion/modules/file/hdrimage.so (linked to libIlmImf-Imf_2_1.so.21 from openexr). The module is dated 2011 and described at http://gwyddion.net/module-list-nocss.en.php#hdrimage
Currently there is no way for the user to guess that compiling openexr will enable some functionalities to be compiled in gwyddion. This added functionality shoudl be exposed to the user as USE flag.
N.B. portage has gwyddion 2.44 but current release is 2.46.
same problem here
Reported automagic deps:
*** Bug 656590 has been marked as a duplicate of this bug. ***