The autotools based build system (configure) is no longer supported and has
been removed.

The use of cmake is experimental.  The implementation is not complete.  It is
untested by continuous integration.  It is not recommended for production use.

The recommended build uses Qt's qmake:

The following options may be set on the qmake command line.

WITH_LIBUSB=no|pkgconfig|system*|included*|custom
  note that libusb is NOT used on windows.
  no: build without libusb-1.0.  functionality will be limited.
  pkgconfig: build with libusb-1.0 found by pkg-config.
  system: build with libusb-1.0 found on system library path and under
    libusb-1.0 on system include path (default, linux, openbsd).
  included: build with libusb-1.0 included with gpsbabel (default, macOS only).
  custom: build with user supplied libusb-1.0. LIBS and INCLUDEPATH may need to
    be set, e.g. LIBS+=... INCLUDEPATH+=...

WITH_SHAPELIB=no|pkgconfig|included*|custom
  no: build without shapelib.  functionality will be limited.
  pkgconfig: build with shapelib found by pkg-config.
  included: build with shapelib included with gpsbabel (default).
  custom: build with user supplied shapelib. LIBS and INCLUDEPATH may need to
    be set, e.g. LIBS+=... INCLUDEPATH+=...

WITH_ZLIB=no|pkgconfig|included*|custom
  no: build without zlib.  functionality will be limited.
  pkgconfig: build with zlib found by pkg-config.
  included: build with zlib included with gpsbabel (default).
  custom: build with user supplied zlib. LIBS and INCLUDEPATH may need to be
    set, e.g. LIBS+=... INCLUDEPATH+=...

CONFIG+=disable-mappreview
  This options disables the map preview feature.  With the feature disabled
  QtWebEngine and QtWebEngineWdigets are not used. Note that QtWebKit and
  QtWebKitWidgets are not longer supported.

DOCVERSION=...
  string appended to documentation location for www.gpsbabel.org.  The default
  value is the version string, e.g. "1.7.0".  This is used by the gpsbabel.org
  target, you are unlikely to need it unless you are maintaining
  www.gpsbabel.org.

WEB=DIR
  Path where the documentation will be stored for www.gpsbabel.org.  This is
  used by the gpsbabel.org target, you are unlikely to need it unless you are
  maintaining www.gpsbabel.org.  The default location is "../babelweb"

Make targets:

check: Run the basic test suite.
check-vtesto: Run valgrind memcheck.
gpsbabel: Build the command line tool.
gpsbabel.hmtl: Create the html documentation.
gpsbabel.org: Create documentation for use on www.gpsbabel.org.
gpsbabel.pdf: Create the pdf documentation.
gui: Build the graphical user interface.
unix-gui: Build the graphical user interface and collect the components for
  distribution.  On Linux the gpsbabel generated components will be under
  gui/GPSBabelFE, any dynamically linked required libraries are not included.
  On macOS an app bundle will be created at gui/GPSBabelFE.app and an apple disk
  image will be created at gui/GPSBabelFE.dmg.

Dependencies:
On non-macOS unix builds by default we now compile in the gpsbabel generated
translation files, i.e. gpsbabelfe_*.qm, gpsbabel_*.qm, as well as
gmapbase.html.  When compiled in these files do not need to be distributed.
These are used by the GUI.  Additional translation files from Qt will also be
used if they are found.  They may be in a package such as qttranslations5-l10n
or qt5-qttranslations.

Windows builds:
  Two build methods are supported with MSVC tools.
  1. "qmake -tp vc" will create a visual studio project that can be built with msbuild.
  2. "qmake" will create a Makefile that can be built with nmake.

