*** Troubleshooting:
-- on ubuntu 20, I receive a failure on mkmf-gnome2 lib loading indicating missing
- mkmf-gnome; "sudo gem install gtk3" workarounds this problem
+- on ubuntu 20, I received a failure on mkmf-gnome2 lib loading
+ indicating missing mkmf-gnome, and "sudo gem install gtk3"
+ workarounded this problem
+
+- on one ubuntu 20, I received a failure compiling the extension with
+ Exiv2::AnyError not found; adding "#include <exiv2/exif.hpp>" in
+ line 27 of ext/rbbooh.cc workarounded this problem
- if that fails on missing GTK header file (gtk.h), you can try to
inject cflags with such a command: