.. env_vars:

====================================================
Environment variables that MRPT looks for
====================================================

The following environment variables may be set to alter some MRPT functionality:

- ``MRPT_BACKTRACE_PRINT_ADDRESS``: Set to ``1`` to show PC (program pointer)
  addresses in mrpt::TCallStackBackTrace::asString() (e.g. in exception backtraces).

- ``MRPT_BACKTRACE_DISABLE_BFD``: Set to ``1`` to disable using BFD while
  generating stack backtraces in mrpt::callStackBackTrace(), falling back to
  ``dladdr()``.

- ``MRPT_EXPR_VERBOSE``: Set to ``1`` to enable extra verbose debug traces for
  mrpt::math::CRuntimeCompiledExpression::eval().

- ``MRPT_CCAMERA_KINECT_TIMEOUT_MS``: Timeout in milliseconds to wait
  for a new frame from a Kinect sensor when using the method
  mrpt::hwdrivers::CCamera::getNextFrame(). Default: ``3000``.

- ``MRPT_HWDRIVERS_DEFAULT_LEAP_SECONDS``: In mrpt::hwdrivers::CGPSInterface, the
  default offset from GPS time to UTC time, for use before any GNSS especific
  message informs on this offset. Default: 17 (valid for 01/2016)

- ``MRPT_HWDRIVERS_VERBOSE`: Set to ``1`` to enable verbose output to ``std::cout``
  from all mrpt::hwdrivers classes. Default: ``0``.

- ``MRPT_WXSUBSYS_TIMEOUT_MS``: The timeout in milliseconds to wait
  in mrpt::gui windows constructors until the wxWidgets thread processes and
  really creates the window, before reporting an error. It's also used in
  the function mrpt::hwdrivers::prepareVideoSourceFromUserSelection().
  Default: ``5000`` in Release builds, ``30000`` in Debug builds.
