poppler-qt4 is unusable because linking against libpoppler-qt4.so results in a link error.
/usr/local/lib/libpoppler-qt4.so: undefined reference to `ArthurOutputDev::startDoc(XRef*)'
/usr/local/lib/libpoppler-qt4.so: undefined reference to `ArthurOutputDev::~ArthurOutputDev()'
/usr/local/lib/libpoppler-qt4.so: undefined reference to `ArthurOutputDev::ArthurOutputDev(QPainter*)'

This error is caused by a poppler configuration.
The above mentioned Arthur rendering backend is only build if QT4 support is requested. But unfortunately the implementation is located within the poppler/ subdirectory and is linked into libpoppler.so. This is no problem if the whole library is build but the poppler-qt4 port just builds the QT4 support forgetting to link the Arthur backend object into the library. That means the resulting libpoppler-qt4.so references the Arthur backend which is not available.

Fix: 

Build the Arthur backend located in the poppler/ subdirectory and link it into the libpoppler-qt4.so.

I think this is more a workaround than a solution. It would be better if the poppler developers would link the Arthur backend into the libpoppler-qt4.so library.
How-To-Repeat: Link against libpoppler-qt4 and reference some class.

For example:

#include <poppler-qt4.h>

int main(int argc, char **argv) {

  Poppler::Document *doc = NULL;

  doc = Poppler::Document::load("/path/to/pdf_file.pdf");

  delete doc;

  return 0;
}

And the QMake file:

TARGET      = poppler-test
TEMPLATE    = app
QT         += core gui xml

INCLUDEPATH += /usr/local/include/poppler/qt4
LIBS        += -lpoppler-qt4

CONFIG(debug, debug|release) {
  TARGET = pdfviewd
}
else {
  TARGET = pdfview
}

MOC_DIR      = .moc
OBJECTS_DIR  = .obj

SOURCES += poppler-test.cc

Set environment variable QMAKESPEC to freebsd-g++