cx oracle ImportError

Question

I followed this tutorial for installing cx_oracle on Mac. After some tweaks it was successful. I was using Mavericks earlier. Then I got an upgrade to El Capitan

Answer 1

This is related to the system integrity protection (SIP) changes in El Capitan, which among other things prevents DYLD_LIBRARY_PATH being inherited by spawned processes.

You can modify the cx_Oracle.so library to use the actual path to the Oracle client library instead of the searched path that no longer works; make sure you have ORACLE_HOME still set to point to your actual instant client location, and also note that the exact path reported by ImportError should be used - the 3071542110 value may vary depending on the version/build of Instant Client you have installed:

export ORACLE_HOME=/usr/local/lib/share/oracle/installclient_11_2

install_name_tool -change \
  /ade/b/3071542110/oracle/rdbms/lib/libclntsh.dylib.11.1 \
  $ORACLE_HOME/libclntsh.dylib.11.1 \
  /Library/Python/2.7/site-packages/cx_Oracle.so

... but then that library can't find another Oracle one:

ImportError: dlopen(/Library/Python/2.7/site-packages/cx_Oracle.so, 2): Library not loaded: /ade/b/3071542110/oracle/ldap/lib/libnnz11.dylib
  Referenced from: /usr/local/lib/share/oracle/installclient_11_2/libclntsh.dylib.11.1
  Reason: image not found

So you'd need to change that library too, which you may be less comfortable with:

install_name_tool -change \
  /ade/b/3071542110/oracle/ldap/lib/libnnz11.dylib \
  $ORACLE_HOME/libnnz11.dylib \
  $ORACLE_HOME/libclntsh.dylib.11.1

Depending on the exact client version/build you may need to make the file writable before running that command, with:

chmod 755 $ORACLE_HOME/libclntsh.dylib.11.1

With those changes I can run the cx_Oracle tests on El Capitan.

More into on install_name_change here.

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It looks like the 12c instant client has been built in a way that avoids this issue, so upgrading to that is gong to be simpler than hacking around int he 11g files.

Answer 2

sample fix with

ln -s /opt/oracle/product/12.1.0/instantclient_12_1/libclntsh.dylib.12.1 /usr/local/lib/libclntsh.dylib.12.1