dlopen fails with file not found when file is in correct path

I have a library built using libtool which is install into the package's library directory, /usr/local/li开发者_开发技巧b/myprog/libmylib.so. I'm dynamically loading the library in my code with libltdl. When I try to load this library on one machine, it works just fine. On another, with the same build and the library installed on the same location, I get a "file not found" error.

If I call lt_dlforeachfile directly before lt_dlopenext (which I use to load the library), then I can see by printing out filenames that the library I need has been found in the search path. But then immediately after, loading it fails with a "file not found" error. Any suggestions?

UPDATE

I have tried switching to using dlopen and explicitly specifying the absolute path to the library. This still works on some systems and not on the other.

It turned out that libltdl was hiding the real error. the "file not found" was from another library that the library I was loading depended on. I discovered this when using dlerror() to print the error messages. After installing the missing library, all is well!