This is probably occurring because Qt3 is installed to a different path from the one the ‘configure’ script is expecting. I advise you to open up the file and look for the section where it checks for the existence of these files. Once you know the expected path, you can look at that location on your system and see if the Qt3 is actually there. If it’s not then you can use ‘apropos qt’ to get the name of the filename the system knows for that program (apropos gives you a list of manpages, you might have to read the appropriate man page to figure out what to look for) and then ‘which Qt3’ (assuming that Qt3 was the correct filename) to determine the installed path. Then you can edit the ‘configure’ file to reflect the true path, and the error should go away.