The new non-libltdl foreign library loading algorithm from 3.0.6 fails to cover common cases regarding how libtool names and installs DLL files. Notably, it fails to recognize when libtool has added the major version number into the filename itself, such as libfoo-1.dll Also, it does not search in binary directories and the PATH for DLL files, where libtool is likely to install DLLs.
Also, just as it handles the libfoo.dll -> cygfoo.dll renaming for cygwin, it should handle the libfoo.dll -> msys-foo.dll renaming for MSYS