I’m sure that’s true but I’ve tried a LOT of variation adding in the libpath argument too pointing it at the various places the libs really have to be… :| One of the multiple examples–

perl -MFFI::CheckLib -E 'find_lib_or_exit recurse => 1, lib => "dcmdat
+a", libpath => "/Users/moo/depot/osirix/Binaries"'
library not found: dcmdata at -e line 1.
[download]

Works for me under Ubuntu (via Windows Subsystem for Linux).

It might be worth checking if the file name matches the search criteria used by FFI::CheckLib. The system uses these regexps (edit - on Mac, which I assume you're using)):

qr{^lib(.*?)\.so(?:\.([0-9]+(?:\.[0-9]+)*))?$}
qr{^lib(.*?)(?:\.([0-9]+(?:\.[0-9]+)*))?\.(?:dylib|bundle)$}
[download]

(see https://metacpan.org/release/FFI-CheckLib/source/lib/FFI/CheckLib.pm#L50 and https://metacpan.org/release/FFI-CheckLib/source/lib/FFI/CheckLib.pm#L70).

When you say it works, do you mean you have DCMTK installed and that worked? I have no trouble with FFI::CheckLib finding standard stuff like xml2 or jpeg or archive. I will look at the regexes versus the lib files too, thanks for suggesting it.