DYLD_LIBRARY does not work as expected

[graeme-winter]

if [ -n "$DYLD_FALLBACK_LIBRARY_PATH" ]; then
  DYLD_FALLBACK_LIBRARY_PATH="$LIBTBX_BUILD/lib:$LIBTBX_BUILD/../conda_base/lib:$DYLD_FALLBACK_LIBRARY_PATH"
  export DYLD_FALLBACK_LIBRARY_PATH
else
  DYLD_FALLBACK_LIBRARY_PATH="$LIBTBX_BUILD/lib:$LIBTBX_BUILD/../conda_base/lib:/usr/X11/lib:/usr/lib::"
  export DYLD_FALLBACK_LIBRARY_PATH
fi

does not do what we would expect

silver-surfer viewer :( $ python3 -c 'import os; print(os.environ["DYLD_FALLBACK_LIBRARY_PATH"])'
/usr/X11/lib:/usr/lib::
silver-surfer viewer :) $ cctbx.python -c 'import os; print(os.environ["DYLD_FALLBACK_LIBRARY_PATH"])'
/Users/graeme/git/dials/build/lib:/Users/graeme/git/dials/build/../conda_base/lib

which means anything which depends on system libraries fails e.g.

OSError: dlopen(libobjc.dylib, 6): image not found

fails

[graeme-winter]

silver-surfer tmp :) $ cat test.sh 
echo $DYLD_FALLBACK_LIBRARY_PATH
if [ -n "$DYLD_FALLBACK_LIBRARY_PATH" ] ; then echo $DYLD_FALLBACK_LIBRARY_PATH ; fi

silver-surfer tmp :) $ ./test.sh 
/usr/X11/lib:/usr/lib::
/usr/X11/lib:/usr/lib::
silver-surfer tmp :) $ bash test.sh 

silver-surfer tmp :) $ 

OK, I suspect we have something to do with SIP happening in here

When I add the #!/bin/bash to the top of the script I reproduce the issue here ->

silver-surfer tmp :) $ cat test.sh 
#!/bin/bash

echo $DYLD_FALLBACK_LIBRARY_PATH
if [ -n "$DYLD_FALLBACK_LIBRARY_PATH" ] ; then echo $DYLD_FALLBACK_LIBRARY_PATH ; fi

silver-surfer tmp :) $ ./test.sh 

-> I do not know what the right solution is here; disable SIP seems nasty.