Bruji

Is there a trick to compiling plugins to work with DVDpedia 6?

I recently got into collecting Laserdiscs and decided I'd try using DVDpedia to catalog them. I took the sample plugin source and modified it to query lddb.com (currently just retrieves the title based on the UPC, but I plan to add all other fields later), and I spent a fair amount of time trying to figure out why isn't it working at all in DVDpedia 6 (tried both in 6.1.0 release and 6.1.0beta190) - the plugin doesn't appear in the Sites prefpane at all (and there's nothing logged in /var/log/system.log). I almost gave up, but then I tried it in DVDpedia 5.7 and it works fine (appears in the Sites prefpane and successfully retrieves the disc data).

To make sure I'm not messing anything with my code, I reproduced this on a clean copy of the sample plugin - it too compiles and works (well, appears in the Sites prefpane) on 5.7 but not on 6.

I'm using Xcode Version 12.5 (12E262) on OSX 11.4, running on a M1 Mac. The only change I had to make to the sample project to get it to compile is to change the target arch from $(ARCHS_STANDARD_32_64_BIT) to x86_64.

Any hints of what could be wrong, or how can I debug this further? (I know approximately nothing about Objective C, but happy to learn more if needed.)

Bob

Hi Bob,

Thank you for the clear description and for trying version 5. Let me take a look and get back to you with what might be stopping the plugin from loading in version 6. As I have yet not pushed the M1 code into the current version so there should be no incompatibility.

Just to make sure it's got nothing to do with M1, I recompiled and reproduced the same issue on another Mac, Intel running 10.14.6 and Xcode 10.3 (10G8).

I had another look at this, and found an interesting message [1]:

Error loading /var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/29B32DEA-D7BC-4940-ADC8-BA824DE79F0D/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb: dlopen(/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/29B32DEA-D7BC-4940-ADC8-BA824DE79F0D/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb, 265): no suitable image found. Did find:
/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/29B32DEA-D7BC-4940-ADC8-BA824DE79F0D/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb: code signature in (/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/29B32DEA-D7BC-4940-ADC8-BA824DE79F0D/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb) not valid for use in process using Library Validation: mapped file has no Team ID and is not a platform binary (signed with custom identity or adhoc?)
/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation<…>

Running codesign -v on the plugin binary shows it's indeed missing a valid signature:

$ codesign -v DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/LDDB
DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/LDDB: invalid Info.plist (plist or signature have been modified)
In architecture: x86_64

I tried re-signing it with an ad-hoc key:
$ codesign -f -s - DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/LDDB
DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/LDDB: replacing existing signature

... which seems to pass codesign verification:

$ codesign -v DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/LDDB
$

But the plugin still fails the same way:

Error loading /var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/2706A02D-D497-447F-8C2B-A1C62FD23101/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb: dlopen(/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/2706A02D-D497-447F-8C2B-A1C62FD23101/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb, 265): no suitable image found. Did find:
/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/2706A02D-D497-447F-8C2B-A1C62FD23101/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb: code signature in (/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation/2706A02D-D497-447F-8C2B-A1C62FD23101/d/DVDpedia6.1.0beta190.app/Contents/Plug-ins/LDDB.plugin/Contents/MacOS/lddb) not valid for use in process using Library Validation: mapped file has no Team ID and is not a platform binary (signed with custom identity or adhoc?)
/var/folders/gq/m7hywqz55kvgthhp5274tqz40000gp/T/AppTranslocation<…>

Googling for the "not valid for use in process using Library Validation" error led me to https://developer.apple.com/forums/thread/128380 which then led to https://developer.apple.com/library/arc ... es/tn2206/, which has a *lot* of detail that I haven't gotten fully through yet, but my initial impression is that Apple isn't very receptive to the scenario of an application using third-party plugins added after build time and not signed by the app developer (see the section on "Nested Code").

The doc does offer a workaround, but it's somewhat clunky: I did a 'codesign --deep -f -s - DVDpedia.app', replacing all signatures with the ad-hoc one, which got the plugin to work on DVDpedia 6. Obviously, that's not a great solution, since it negates all the security benefit of Gatekeeper and it'll need re-signing after an update, but at least I can keep working on the plugin using DVDpedia 6, not relying on 5.7.

Bob

[1] ...which was probably there all along in Console.app, but I'd thought that grepping /var/log/system.log would also show it, which clearly isn't the case. Did I mention I don't know the first thing about Mac development :) ?

Thanks for that. Could you please send all of that direct to: support@bruji.com