title: Qt Creator release mode undefined references to std::out_of_range
body: <p>I'm writing a small C++ program (with a GUI) with Qt Creator and compiling with MinGW. Everything works fine when I compile the project in debug mode but as soon as I move to release mode I get compiler errors:</p>
  
  <pre><code>undefined reference to 'std::out_of_range::~out_of_range()'         thread.cpp
  </code></pre>
  
  <p>When I click on the error I also get:</p>
  
  <pre><code>File not found: thread.cpp
  </code></pre>
  
  <p>I have looked through my Boost installation and found thread.cpp and it should be on the include path for my project.</p>
  
  <p>Any ideas?</p>
  
  <p>EDIT: Here is my .pro file:</p>
  
  <pre><code>#-------------------------------------------------
  #
  # Project created by QtCreator 2012-08-10T12:09:39
  #
  #-------------------------------------------------
  
  QT       += core gui
  
  TARGET = GeneDropWin
  TEMPLATE = app
  
  SOURCES += main.cpp \
      genedrop.cpp \
      mainbody.cpp \
      biofunctions.cpp \
      fileio.cpp \
      settings.cpp
  
  HEADERS  += genedrop.h \
      geneclasses.h \
      paramclass.h \
      mainbody.h \
      biofunctions.h \
      fileio.h \
      geneclasses.h \
      settings.h
  
  FORMS    += genedrop.ui \
      settings.ui
  
  #Stuff I've added
  INCLUDEPATH += "C:\\Program Files\\boost_1_50_0"
  LIBS += -L"C:\\Program Files\\boost_1_50_0\\stage\\lib" -lboost_thread-mgw46-mt-1_50 -lboost_system-mgw46-mt-1_50 -lboost_date_time-mgw46-mt-1_50 -lboost_chrono-mgw46-mt-1_50
  CONFIG += static \
      release
  
  RESOURCES += \
      NIABLogo.qrc
  </code></pre>