Fedora 21 - kernel 3.18.5-201.fc21.x86_64
QCAD exits immediately. This started with version 3.8.0.
3.7.7 is ok with respect to startup.

/home/wrsturm/opt/qcad-3.8.1-linux-x86_64/qcad
Debug: RCamScriptsPlugin: init
Debug: RDwgPlugin::init: trial
Debug: RDxfPlugin::init
Debug: RHelpPlugin::init
Debug: RProScriptsPlugin::init
Debug: loading patterns from file: "/home/wrsturm/opt/qcad-3.8.1-linux-x86_64/linetypes/metric/qcadiso.lin"
Debug: loading patterns from file: "/home/wrsturm/opt/qcad-3.8.1-linux-x86_64/linetypes/imperial/qcad.lin"
Debug: TIMER: 107 ms - "loading add-ons"
Debug: TIMER: 567 ms - "initializing add-ons"
Warning: QSqlDatabasePrivate::removeDatabase: connection 'library_browser_connection' is still in use, all queries will cease to work.
Warning: QSqlDatabasePrivate::addDatabase: duplicate connection name 'library_browser_connection', old connection removed.
Debug: Rebuilding DB...
Debug: checking for QCAD Pro updates...
Debug: no updates available
Debug: "DWG" : disabling (> 100 runs)
Warning: WidgetFactory: File /home/wrsturm/opt/qcad-3.8.1-linux-x86_64/scripts/TrialExpiredDialog.ui does not exist
Warning: RScriptHandlerEcma::eval: script engine exception: "TypeError: Result of expression 'dlg' [undefined] is not an object."
Warning: "<anonymous>()@:scripts/Cam/Widgets/TrialExpired/TrialExpired.js:276"
Debug: "Pro Tools" : disabling (> 100 runs)
Warning: RScriptHandlerEcma::eval: script engine exception: "TypeError: Result of expression 'dlg' [undefined] is not an object."
Warning: "<anonymous>()@:scripts/Cam/Widgets/TrialExpired/TrialExpired.js:276"
Warning: At least one uncaught exception:
Warning: "<anonymous>()@:scripts/Cam/Widgets/TrialExpired/TrialExpired.js:276"
Debug: "<global>() at -1"