[Megatron-UK]

Hi, I can't seem to get 0.6.40 built from source to run on my x64 Debian Lenny system. The binary is not applicable as Debian 5 has GLIBC 2.9.

All dependencies listed on the Linux install page are present (all have been built and installed under /usr/local so as not to conflict with packaged OS versions).

Python 2.6.4
Qt 4.6.2
PyQt 4.7
ImageMagick 6.5.9-6
BeautifulSoup 3.0.8
Podofo 0.7.0
Mechanize 0.1.11
Sip 4.10
Poppler 0.12.3
Libxml 2.2.4
cssutils 0.9.7a2

The code builds cleanly but immediately segfaults on launching the gui:

elderthing:/usr/local/src/calibre# PODOFO_INC_DIR=/usr/local/include/podofo PODOFO_LIB_DIR=/usr/local/lib LDFLAGS=-L/usr/local/python26/lib python setup.py install

*
* Running build
*


####### Building extension pdfreflow #######
g++ -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -DPNG_SKIP_SETJMP_CHECK -I/usr/local/include/poppler -I/usr/local/include/ImageMagick -I/usr/include -c /extra/local/src/calibre/src/calibre/ebooks/pdf/main.cpp -o /extra/local/src/calibre/build/objects/pdfreflow/main.o
g++ -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -DPNG_SKIP_SETJMP_CHECK -I/usr/local/include/poppler -I/usr/local/include/ImageMagick -I/usr/include -c /extra/local/src/calibre/src/calibre/ebooks/pdf/links.cpp -o /extra/local/src/calibre/build/objects/pdfreflow/links.o
g++ -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -DPNG_SKIP_SETJMP_CHECK -I/usr/local/include/poppler -I/usr/local/include/ImageMagick -I/usr/include -c /extra/local/src/calibre/src/calibre/ebooks/pdf/reflow.cpp -o /extra/local/src/calibre/build/objects/pdfreflow/reflow.o
g++ -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -DPNG_SKIP_SETJMP_CHECK -I/usr/local/include/poppler -I/usr/local/include/ImageMagick -I/usr/include -c /extra/local/src/calibre/src/calibre/ebooks/pdf/images.cpp -o /extra/local/src/calibre/build/objects/pdfreflow/images.o
g++ -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -DPNG_SKIP_SETJMP_CHECK -I/usr/local/include/poppler -I/usr/local/include/ImageMagick -I/usr/include -c /extra/local/src/calibre/src/calibre/ebooks/pdf/fonts.cpp -o /extra/local/src/calibre/build/objects/pdfreflow/fonts.o
Linking pdfreflow


 g++ /extra/local/src/calibre/build/objects/pdfreflow/main.o /extra/local/src/calibre/build/objects/pdfreflow/links.o /extra/local/src/calibre/build/objects/pdfreflow/reflow.o /extra/local/src/calibre/build/objects/pdfreflow/images.o /extra/local/src/calibre/build/objects/pdfreflow/fonts.o -o /extra/local/src/calibre/src/calibre/plugins/pdfreflow.so -Wall -L/usr/local/python26/lib -shared -lpython2.6 -L/usr/lib -lpoppler -lMagickWand -lMagickCore -lpng 



####### Building extension lzx #######
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/lzx -c /extra/local/src/calibre/src/calibre/utils/lzx/compressor.c -o /extra/local/src/calibre/build/objects/lzx/compressor.o
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/lzx -c /extra/local/src/calibre/src/calibre/utils/lzx/lzxc.c -o /extra/local/src/calibre/build/objects/lzx/lzxc.o
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/lzx -c /extra/local/src/calibre/src/calibre/utils/lzx/lzxd.c -o /extra/local/src/calibre/build/objects/lzx/lzxd.o
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/lzx -c /extra/local/src/calibre/src/calibre/utils/lzx/lzxmodule.c -o /extra/local/src/calibre/build/objects/lzx/lzxmodule.o
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/lzx -c /extra/local/src/calibre/src/calibre/utils/lzx/lzc.c -o /extra/local/src/calibre/build/objects/lzx/lzc.o
Linking lzx


 gcc /extra/local/src/calibre/build/objects/lzx/compressor.o /extra/local/src/calibre/build/objects/lzx/lzxc.o /extra/local/src/calibre/build/objects/lzx/lzxd.o /extra/local/src/calibre/build/objects/lzx/lzxmodule.o /extra/local/src/calibre/build/objects/lzx/lzc.o -o /extra/local/src/calibre/src/calibre/plugins/lzx.so -Wall -L/usr/local/python26/lib -shared -lpython2.6 



####### Building extension fontconfig #######
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/usr/include/fontconfig -c /extra/local/src/calibre/src/calibre/utils/fonts/fontconfig.c -o /extra/local/src/calibre/build/objects/fontconfig/fontconfig.o
Linking fontconfig


 gcc /extra/local/src/calibre/build/objects/fontconfig/fontconfig.o -o /extra/local/src/calibre/src/calibre/plugins/fontconfig.so -Wall -L/usr/local/python26/lib -shared -lpython2.6 -L/usr/lib -lfontconfig 



####### Building extension msdes #######
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/msdes -c /extra/local/src/calibre/src/calibre/utils/msdes/des.c -o /extra/local/src/calibre/build/objects/msdes/des.o
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/extra/local/src/calibre/src/calibre/utils/msdes -c /extra/local/src/calibre/src/calibre/utils/msdes/msdesmodule.c -o /extra/local/src/calibre/build/objects/msdes/msdesmodule.o
Linking msdes


 gcc /extra/local/src/calibre/build/objects/msdes/des.o /extra/local/src/calibre/build/objects/msdes/msdesmodule.o -o /extra/local/src/calibre/src/calibre/plugins/msdes.so -Wall -L/usr/local/python26/lib -shared -lpython2.6 



####### Building extension cPalmdoc #######
gcc -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -c /extra/local/src/calibre/src/calibre/ebooks/compression/palmdoc.c -o /extra/local/src/calibre/build/objects/cPalmdoc/palmdoc.o
Linking cPalmdoc


 gcc /extra/local/src/calibre/build/objects/cPalmdoc/palmdoc.o -o /extra/local/src/calibre/src/calibre/plugins/cPalmdoc.so -Wall -L/usr/local/python26/lib -shared -lpython2.6 



####### Building extension podofo #######
g++ -O3 -Wall -DNDEBUG -fno-strict-aliasing -pipe -fPIC -march=core2 -mtune=core2 -msse2 -msse3 -mssse3 -pipe -mfpmath=sse -malign-double -pthread -I/usr/local/python26/include/python2.6 -I/usr/local/include/podofo -c /extra/local/src/calibre/src/calibre/utils/podofo/podofo.cpp -o /extra/local/src/calibre/build/objects/podofo/podofo.o
Linking podofo


 g++ /extra/local/src/calibre/build/objects/podofo/podofo.o -o /extra/local/src/calibre/src/calibre/plugins/podofo.so -Wall -L/usr/local/python26/lib -shared -lpython2.6 -L/usr/local/lib -lpodofo 



####### Building extension pictureflow #######
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIC -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o pictureflow.o ../../../../src/calibre/gui2/pictureflow/pictureflow.cpp
../../../../src/calibre/gui2/pictureflow/pictureflow.cpp:1382: warning: unused parameter ‘index’
../../../../src/calibre/gui2/pictureflow/pictureflow.cpp:1383: warning: unused parameter ‘index’
/usr/bin/moc-qt4 -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. ../../../../src/calibre/gui2/pictureflow/pictureflow.h -o moc_pictureflow.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIC -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o moc_pictureflow.o moc_pictureflow.cpp
rm -f libpictureflow.so.1.0.0 libpictureflow.so libpictureflow.so.1 libpictureflow.so.1.0
g++ -shared -Wl,-soname,libpictureflow.so.1 -o libpictureflow.so.1.0.0 pictureflow.o moc_pictureflow.o   -L/usr/lib -lQtGui -lQtCore -lpthread 
ln -s libpictureflow.so.1.0.0 libpictureflow.so
ln -s libpictureflow.so.1.0.0 libpictureflow.so.1
ln -s libpictureflow.so.1.0.0 libpictureflow.so.1.0
/usr/local/python26/bin/sip -w -c /extra/local/src/calibre/build/pyqt/pictureflow -b /extra/local/src/calibre/build/pyqt/pictureflow/pictureflow.sip.sbf -I/usr/local/python26/share/sip/PyQt4 -x VendorID -t WS_X11 -x PyQt_NoPrintRangeBug -t Qt_4_6_0 -x Py_v3 -g /extra/local/src/calibre/src/calibre/gui2/pictureflow/pictureflow.sip
g++ -c -pipe -fPIC -O2 -Wall -W -D_REENTRANT -DNDEBUG -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -I. -I/extra/local/src/calibre/src/calibre/gui2/pictureflow -I/usr/local/python26/include/python2.6 -I/usr/local/qt4/mkspecs/default -I/usr/local/qt4/include/QtCore -I/usr/local/qt4/include/QtGui -I/usr/local/qt4/include -I/usr/X11R6/include -o sippictureflowcmodule.o sippictureflowcmodule.cpp
g++ -c -pipe -fPIC -O2 -Wall -W -D_REENTRANT -DNDEBUG -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -I. -I/extra/local/src/calibre/src/calibre/gui2/pictureflow -I/usr/local/python26/include/python2.6 -I/usr/local/qt4/mkspecs/default -I/usr/local/qt4/include/QtCore -I/usr/local/qt4/include/QtGui -I/usr/local/qt4/include -I/usr/X11R6/include -o sippictureflowPictureFlow.o sippictureflowPictureFlow.cpp
g++ -c -pipe -fPIC -O2 -Wall -W -D_REENTRANT -DNDEBUG -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -I. -I/extra/local/src/calibre/src/calibre/gui2/pictureflow -I/usr/local/python26/include/python2.6 -I/usr/local/qt4/mkspecs/default -I/usr/local/qt4/include/QtCore -I/usr/local/qt4/include/QtGui -I/usr/local/qt4/include -I/usr/X11R6/include -o sippictureflowFlowImages.o sippictureflowFlowImages.cpp
g++ /extra/local/src/calibre/build/pyqt/pictureflow/qt/pictureflow.o /extra/local/src/calibre/build/pyqt/pictureflow/qt/moc_pictureflow.o -shared -Wl,-O1 -Wl,-rpath,/usr/local/qt4/lib -Wl,--version-script=pictureflow.exp -o pictureflow.so sippictureflowcmodule.o sippictureflowPictureFlow.o sippictureflowFlowImages.o -L/usr/local/qt4/lib -L/usr/X11R6/lib64 -lQtCore -L/usr/local/qt4/lib -lpthread -lQtGui -L/usr/local/qt4/lib -L/usr/X11R6/lib64 -lQtCore -L/usr/local/qt4/lib -lpthread -lXext -lX11 -lm -lpthread

####### Building extension progress_indicator #######
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIC -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o QProgressIndicator.o ../../../../src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
../../../../src/calibre/gui2/progress_indicator/QProgressIndicator.h: In constructor ‘QProgressIndicator::QProgressIndicator(QWidget*, int)’:
../../../../src/calibre/gui2/progress_indicator/QProgressIndicator.h:90: warning: ‘QProgressIndicator::m_displayedWhenStopped’ will be initialized after
../../../../src/calibre/gui2/progress_indicator/QProgressIndicator.h:89: warning:   ‘int QProgressIndicator::m_displaySize’
../../../../src/calibre/gui2/progress_indicator/QProgressIndicator.cpp:5: warning:   when initialized here
/usr/bin/moc-qt4 -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. ../../../../src/calibre/gui2/progress_indicator/QProgressIndicator.h -o moc_QProgressIndicator.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIC -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o moc_QProgressIndicator.o moc_QProgressIndicator.cpp
rm -f libprogress_indicator.so.1.0.0 libprogress_indicator.so libprogress_indicator.so.1 libprogress_indicator.so.1.0
g++ -shared -Wl,-soname,libprogress_indicator.so.1 -o libprogress_indicator.so.1.0.0 QProgressIndicator.o moc_QProgressIndicator.o   -L/usr/lib -lQtGui -lQtCore -lpthread 
ln -s libprogress_indicator.so.1.0.0 libprogress_indicator.so
ln -s libprogress_indicator.so.1.0.0 libprogress_indicator.so.1
ln -s libprogress_indicator.so.1.0.0 libprogress_indicator.so.1.0
/usr/local/python26/bin/sip -w -c /extra/local/src/calibre/build/pyqt/progress_indicator -b /extra/local/src/calibre/build/pyqt/progress_indicator/QProgressIndicator.sip.sbf -I/usr/local/python26/share/sip/PyQt4 -x VendorID -t WS_X11 -x PyQt_NoPrintRangeBug -t Qt_4_6_0 -x Py_v3 -g /extra/local/src/calibre/src/calibre/gui2/progress_indicator/QProgressIndicator.sip
g++ -c -pipe -fPIC -O2 -Wall -W -D_REENTRANT -DNDEBUG -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -I. -I/extra/local/src/calibre/src/calibre/gui2/progress_indicator -I/usr/local/python26/include/python2.6 -I/usr/local/qt4/mkspecs/default -I/usr/local/qt4/include/QtCore -I/usr/local/qt4/include/QtGui -I/usr/local/qt4/include -I/usr/X11R6/include -o sipprogress_indicatorcmodule.o sipprogress_indicatorcmodule.cpp
g++ -c -pipe -fPIC -O2 -Wall -W -D_REENTRANT -DNDEBUG -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -I. -I/extra/local/src/calibre/src/calibre/gui2/progress_indicator -I/usr/local/python26/include/python2.6 -I/usr/local/qt4/mkspecs/default -I/usr/local/qt4/include/QtCore -I/usr/local/qt4/include/QtGui -I/usr/local/qt4/include -I/usr/X11R6/include -o sipprogress_indicatorQProgressIndicator.o sipprogress_indicatorQProgressIndicator.cpp
g++ /extra/local/src/calibre/build/pyqt/progress_indicator/qt/moc_QProgressIndicator.o /extra/local/src/calibre/build/pyqt/progress_indicator/qt/QProgressIndicator.o -shared -Wl,-O1 -Wl,-rpath,/usr/local/qt4/lib -Wl,--version-script=progress_indicator.exp -o progress_indicator.so sipprogress_indicatorcmodule.o sipprogress_indicatorQProgressIndicator.o -L/usr/local/qt4/lib -L/usr/X11R6/lib64 -lQtCore -L/usr/local/qt4/lib -lpthread -lQtGui -L/usr/local/qt4/lib -L/usr/X11R6/lib64 -lQtCore -L/usr/local/qt4/lib -lpthread -lXext -lX11 -lm -lpthread

*
* Running gui
*

Segmentation fault
elderthing:/usr/local/src/calibre#

CFLAGS are not the issue - unsetting them makes no difference to the outcome.

If I run python setup.py install a second time, it will install Calibre to /usr/local/python26/lib/calibre as expected, but the Calibre gui just segfaults every single time.

Calibre-debug offers no output.

A stack trace on calibre shows the following error coming from src/calibre/gui2/library.py:

open("/usr/local/python26/lib/calibre/calibre/gui2/library.py", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=43717, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc12e169000
read(3, "from calibre.ebooks.metadata impo"..., 4096) = 4096
write(2, " "..., 4 ) = 4
write(2, "COLOR = QColor(\"blue\")\n"..., 26COLOR = QColor("blue")
) = 26
close(3) = 0
munmap(0x7fc12e169000, 4096) = 0
write(2, "TypeError"..., 9TypeError) = 9
write(2, ": "..., 2: ) = 2
write(2, "unable to convert a Python 'str' "..., 67unable to convert a Python 'str' object to a C++ 'QString' instance) = 67
write(2, "\n"..., 1
) = 1
rt_sigaction(SIGINT, {SIG_DFL}, {0x7fc12db4bda0, [], SA_RESTORER, 0x7fc12d7fba80}, 8) = 0
getpid() = 10050
munmap(0x414fc000, 8192) = 0
close(12) = 0
munmap(0x7fc12e159000, 4096) = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

I have experimented with changing the way that line is define in src/calibre/gui2/library.py from:

COLOR = QColor("blue")

to...

COLOR = QColor(QString("blue"))

... adding the import of QString from QTCore of course. This remove the Python 'str' to C++ 'QString' error, but still leaves me with a segfault and no further indication as to what causes it.

At this point if I run calibre again under strace I get two different traces, depending on whether running as root, or as a normal user:

Normal user last few lines:

open("/usr/local/python26/share/calibre/images/mimetypes/zero.svg", O_RDONLY|O_CLOEXEC) = 20
fcntl(20, F_SETFD, FD_CLOEXEC) = 0
fstat(20, {st_mode=S_IFREG|0644, st_size=7420, ...}) = 0
fstat(20, {st_mode=S_IFREG|0644, st_size=7420, ...}) = 0
read(20, "<?xml version=\"1.0\" encoding=\"UTF"..., 16384) = 7420
read(20, ""..., 8964) = 0
read(20, ""..., 772) = 0
read(20, ""..., 16384) = 0
read(20, ""..., 8192) = 0
fstat(20, {st_mode=S_IFREG|0644, st_size=7420, ...}) = 0
close(20) = 0
open("/usr/local/python26/share/calibre/images/mimetypes/zero.svg", O_RDONLY|O_CLOEXEC) = 20
fcntl(20, F_SETFD, FD_CLOEXEC) = 0
fstat(20, {st_mode=S_IFREG|0644, st_size=7420, ...}) = 0
fstat(20, {st_mode=S_IFREG|0644, st_size=7420, ...}) = 0
read(20, "<?xml version=\"1.0\" encoding=\"UTF"..., 16384) = 7420
read(20, ""..., 8964) = 0
read(20, ""..., 772) = 0
read(20, ""..., 16384) = 0
read(20, ""..., 8192) = 0
fstat(20, {st_mode=S_IFREG|0644, st_size=7420, ...}) = 0
close(20) = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

Last few lines of stack trace as root:

read(20, "dead_diaeresis> <Greek_iota> \t: \""..., 4096) = 4096
read(20, " U1FE1 # GREEK SMALL LETTER UPSI"..., 4096) = 4096
read(20, " \t: \"\341\277\254\" U1FEC # GREEK CAPI"..., 4096) = 4096
read(20, "\"\341\277\270\" U1FF8 # GREEK CAPITAL LET"..., 4096) = 4096
read(20, "SCRIPT LATIN SMALL LETTER N\n<Mult"..., 4096) = 4096
read(20, "ESIS\n<Multi_key> <underbar> <pare"..., 4096) = 4096
read(20, "ti_key> <U227C> <U0338> \t: \"\342\213\240\" "..., 4096) = 4096
read(20, " \"\342\221\255\" U246D # CIRCLED NUMBER F"..., 4096) = 4096
read(20, "8 # CIRCLED LATIN CAPITAL LETTER "..., 4096) = 4096
read(20, "\201\222\" U3052 # HIRAGANA LETTER GE\n"..., 4096) = 4096
read(20, " U3193 # IDEOGRAPHIC ANNOTATION T"..., 4096) = 4096
read(20, "key> <parenleft> <2> <4> <parenri"..., 4096) = 4096
read(20, "renleft> <KP_3> <KP_1> <parenrigh"..., 4096) = 4096
read(20, "3279 # CIRCLED HANGUL THIEUTH A\n<"..., 4096) = 4096
read(20, "OGRAPH STUDY\n<Multi_key> <parenle"..., 4096) = 4096
read(20, "\n<Multi_key> <parenleft> <4> <KP_"..., 4096) = 4096
read(20, "U\n<Multi_key> <parenleft> <kana_N"..., 4096) = 4096
read(20, "B39 # HEBREW LETTER YOD WITH DAGE"..., 4096) = 3348
read(20, ""..., 4096) = 0
close(20) = 0
munmap(0x7fe9710c7000, 4096) = 0
select(8, [7], [7], NULL, NULL) = 1 (out [7])
writev(7, [{"\2\2\4\0>\1\0\0\0\10\0\0000@@\0"..., 16}], 1) = 16
read(7, 0x39ce4d4, 4096) = -1 EAGAIN (Resource temporarily unavailable)
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

At this point I'm all out of ideas and hoping that someone with a bit more knowledge of the internals of Calibre will know what is going on (for example... why the initial Python 'str' to 'QString' error when the original code is not doing explicit type casting???).