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9278 :: How to let nim know to search an additional path for linking a lib?

• matthesoundman (orginal) [2022-07-03T01:39:33+02:00] view original

  Hello,

  Is there a way to add another path to the default search path for libraries? Or what argument do I pass and specify the path to search?

  I tried: nim c --path:/opt/homebrew/lib/ --run --define:nimDebugDlOpen myfile.nim

  It always fails even though the lib is present.

  
  Hint: /Users/user/Desktop/myfile  [Exec]
  dlopen(libSDL2.dylib, 0x0002): tried: 'libSDL2.dylib' (no such file), '/usr/local/lib/libSDL2.dylib' (no such file), '/usr/lib/libSDL2.dylib' (no such file), '/Users/user/Desktop/libSDL2.dylib' (no such file)
  could not load: libSDL2.dylib
  Run

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• Symb0lica (orginal) [2022-07-03T11:33:49+02:00] view original

  Use --passL to add options to link, e.g.

  --passL="-L/your/lib/path"
  Run

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• matthesoundman (orginal) [2022-07-03T22:01:17+02:00] view original

  Thanks.

  I tried your suggestion like so. nim c --passL:"-L/opt/homebrew/lib" --run --define:nimDebugDlOpen myfile.nim

  It still did not search the path.

  
  Hint: /Users/user/Documents/nim/myfile  [Exec]
  dlopen(libSDL2.dylib, 0x0002): tried: 'libSDL2.dylib' (no such file), '/usr/local/lib/libSDL2.dylib' (no such file), '/usr/lib/libSDL2.dylib' (no such file), '/Users/user/Documents/nim/libSDL2.dylib' (no such file)
  could not load: libSDL2.dylib
  Error: execution of an external program failed: '/Users/user/Documents/nim/myfile '
  Run

  I don't know what defines the hard coded search paths of /usr/local/lib /usr/lib.

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• matthesoundman (orginal) [2022-07-03T22:08:10+02:00] view original

  Also, I would expect the binary after compilation to list the lib dependency.

  Terminal Output

  
  $ otool -L myfile
  myfile:
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1311.100.3)
  Run

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• Symb0lica (orginal) [2022-07-03T22:54:33+02:00] view original

  Apologies - I jumped to conclusions based on the title of the post. My answer would be relevant for static linked libraries, but I now realise the library is being dynamically loaded. You could try making sure that the environment variable LD_LIBRARY_PATH is set and includes the directory where the library exists (see https://man7.org/linux/man-pages/man3/dlopen.3.html)

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• matthesoundman (orginal) [2022-07-03T23:27:07+02:00] view original

  No apologies necessary. Really appreciate the help.

  I am still seeing same issue with setting the externs.

  I am not sure, but something seems wrong with the executable. I pointed out earlier there is no dependency to link to libSDL2.dylib. It purely is being suggested for linking during runtime (which I don't know how or where this is specified).

  Something is supplying paths to the dlopen command.

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• sls1005 (orginal) [2022-07-04T04:54:04+02:00] view original

  You are not linking to the shared library. Instead, it's loaded using dlopen, so it's not shown. Maybe you have to specify the whole path.

  dlopen("/opt/homebrew/lib/libSDL2.dylib", 2)
  Run

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• matthesoundman (orginal) [2022-07-05T19:44:05+02:00] view original

  Where do I specify?

  dlopen("/opt/homebrew/lib/libSDL2.dylib", 2)
  Run

  This is the content from myfile.nim.

  import pixels
  
  putPixel(5, 9)
  putPixel(11, 18, Red)
  Run

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• matthesoundman (orginal) [2022-07-05T19:50:43+02:00] view original

  NVM. Question closed.

  I had tried appending. to $DYLD_LIBRARY_PATH and it actually worked this time.

  Thanks all.

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• matthesoundman (orginal) [2022-07-06T05:29:08+02:00] view original

  Thought about this a little more. How does this support the dependency free aspect of the language? I actually found this to be irritating because there was indeed a dependency, but it was not explicit in the mach-o header nor could I determine who was calling dlopen. To better educate myself I would appreciate some insight into how this all works from my example (walking through the context in Mastering Nim).

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