Update build-unix.md

[tedjweb]

./configure LDFLAGS=-L/usr/local/BerkeleyDB.4.8/lib/ CPPFLAGS=-I/usr/local/BerkeleyDB.4.8/include/

[BitcoinPullTester]

Automatic sanity-testing: PASSED, see http://jenkins.bluematt.me/pull-tester/911937b7dea3315a304e83a543d136d930d19b21 for binaries and test log.
This test script verifies pulls every time they are updated. It, however, dies sometimes and fails to test properly. If you are waiting on a test, please check timestamps to verify that the test.log is moving at http://jenkins.bluematt.me/pull-tester/current/
Contact BlueMatt on freenode if something looks broken.

[Altoidnerd]

/bitcoin-qt: error while loading shared libraries: libdb_cxx-4.8.so: cannot open shared object file: No such file or directory

I have received this error message from time to time.

[sipa]

@Altoidnerd That means you don't have db_cxx 4.8 installed. That has nothing to do with this PR.

[laanwj]

@Altoidnerd if you build berkelydb from source, it's recommended to only build the static libraries. Otherwise you have to fumble around with LD_LIBRARY_PATH to make sure it can find the .so at runtime.

[laanwj]

For clarity I suggest putting double quotes around the options, i.e.
LDFLAGS="-L/usr/local/BerkeleyDB.4.8/lib/" CPPFLAGS="-I/usr/local/BerkeleyDB.4.8/include/"

Also: does redefining those options lose any built-in options like optimization flags? (I know that redefining CXXFLAGS does...) I'd still prefer to have specific settings to specify the BDB paths (see #3921).

[Altoidnerd]

@sipa If this PR is about conflicting bdb versions...well prior to #4063, I may have accumulated a few as there is even more than one 4.8. I'm not entirely sure though.

[laanwj]

Closing in favor of #4114