Lessons_learned.txt

Here are some notes about lessons learned when deploying XALT in the
field.

* How the compiler finds the linker: The GCC compilers find the linker
  by using $COMPILER_PATH.  If this isn't set then it finds the one
  with the built-in binutils.  However $COMPILER_PATH is set before
  linking then it uses that instead.

  Note that one can configure gcc to hardcode the path to ld.

* The linker can be called ld, ld.gold or x86_64-linux-gnu-ld

* When building Intel PIN library, it caused problems when building a
  shared library.  So XALT now doesn't include xalt_initialize.o etc
  when building a shared library.
  
* Installers of XALT really want to install XALT by setting the prefix
  to /apps/xalt/$VERSION.  which means that the real location is
  /apps/xalt/$VERSION/xalt/xalt/*

  This is a problem because they will say set:
  /apps/xalt/2.0.7/xalt/xalt.  Then when they install the next version
  (say /apps/xalt/2.0.8/xalt/xalt) all the old apps built with 2.0.7
  won't be able to find xalt_run_submission.

* As of 2.0.9 XALT checks to see if it can find xalt_run_submission.
  It also records in xalt_configuration_report whether it was a
  "BAD_INSTALL" or not.