Looks like the solution (as listed at https://cutecoder.org/programming/shared-framework-hardened-runtime/) is either:

1. sign the Pd app and disable plugin validation; or
2. use externals built for a min version of macOS 10.9

I've tried option 1 by "ad-goc" signing Millers Pd 0.50-2 build with the library validation entitlement disabled:

http://docs.danomatika.com/pdbuilds/0.51/Pd-0.50-2-signed.zip

Please test.

On Dec 11, 2019, at 11:23 PM, Dan Wilcox <danomatika@gmail.com> wrote:

We might need to add an entitlements file which specifies which things are "allowed," one of which is loading non-signed external libs. I ran into this with a project at work which uses libpd and loads a couple externals.

On Dec 11, 2019, at 9:56 PM, Kevin Haywood <khaywood@ucsd.edu> wrote:

I just discovered the huge headache of the notarization system under Catalina: the OS will prevent loading of every non-notarized *external* that you try to load. ...

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Dan Wilcox
@danomatika
danomatika.com
robotcowboy.com