'dlopen' ignore LD_LIBRARY_PATH on macOS 12.2, 12.3

Hi,

'dlopen' ignores the search path that is defined for LD_LIBRARY_PATH on macOS 12.2 and 12.3, even-though the path doesn't contain slash.

LD_LIBRARY_PATH is set as follows (before the call): export LD_LIBRARY_PATH="/Users/administrator/Desktop/Test/"

'test_library.dylib' is located under '/Users/administrator/Desktop/Test/'

The c call at the application looks as follows (The application is built by Xcode 13): handle = dlopen("test_library.dylib", RTLD_LAZY);

I see that the error i get, when calling to dlopen, is that test_library.dylib isn't found. From the error it looks that library loader doesn't search the library at the search path that is defined for LD_LIBRARY_PATH. During the call, the LD_LIBRARY_PATH contains the path.

If i set this path to DYLD_LIBRARY_PATH, dlopen finds 'test_library.dylib' and everything works as expected.

I didn't find any documentation for this issue, therefore, is it a known limitation? Is there a workaround?

Thx, Moshe.

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If i set this path to DYLD_LIBRARY_PATH, dlopen finds test_library.dylib and everything works as expected.

AFAICT dyld3 never supported LD_LIBRARY_PATH and, now that dyld2 and dyld3 are merged into dyld4, that lack of support has come to the Mac. I suspect that this was deliberate but I can’t find any concrete evidence for that.

If you’d like me to confirm this for real, open a DTS tech support incident for this; that’ll allow me time to investigate properly.

Regardless, it’s clear that the dlopen man page could do with an update and I encourage you to file a bug requesting that. Please post your bug number, just for the record.

Regardless of all of the above, relying on dynamic linker search path environment variables is something I recommend against, especially for dlopen where you can use whatever algorithm you want to find libraries and then pass dlopen a full path. So, why are you doing this?

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I am aware of the cons of relying on dynamic linker search path environment variable. I am just checking some old code.

I filed a bug - FB10004087

Thx, Moshe.

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myud
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I filed a bug - FB10004087

Thanks.

I was curious about the death of LD_LIBRARY_PATH so I asked the linker team about this. Its removal was definitely deliberate. The rationale was that it was basically redundant versus DYLD_LIBRARY_PATH, but harder to support due to historical baggage. We removed the discussion of it from the dyld man page but missed it in the dlopen one.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

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eskimo
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