Linker Error: framework not found MPLibrary

After considerable effort I finally stamped out all incompatibilities from my previous RS project and tried to run under XOJO only to get this error:

Linking Executable
ld: framework not found MPLibrary

Googling reveals precious little, certainly nothing connected with XOJO or macOS. I don’t even know what this lib is (is it multiprocessor or multiple precision?).

I have MBS plugins, and my own plugin written in C/C++/Xcode that works fine in my RS project (as 32 bit; I recompiled as 64 bit for the XOJO port).

I don’t even know where to start looking. Is this my fault or something deep inside XOJO (the error log includes a msg telling me to copy the error and submit a bug report; once I get a sense that this is not my doing I will submit a bug report).

Any insights greatly appreciated.

If it’s on macOS that might be something to do with multiprocessing < >

Any declares in your code?
What plugins are you calling?

MPLibrary is from Mac OS Classic, > 10 years ago.

Check declares.

Thx folks, quite right, I had an obscure Declare that caused the error.