[Qt-creator] Segmentation fault in Ubuntu x64, Qt 5.3.1

[Guido Seifert]

Just from a gut feeling I'd say this is the typical Qt4/Qt5 problem. Somewhere you have a plugin or lib,
which links against qt4, but which is also used by your qt5 program. This is a sure recipe for unexplainable 
seg faults.

Guido

On Tue, 9 Sep 2014 08:32:51 +0200
"Niels Becker" <Niels-Becker at gmx.de> wrote:

> Hello everybody,
> 
> first of all I am not sure if this is a bug or a configuration / hardware issuse.
> 
> My machine is a virtual headless server with
> 2 GB Ram
> Single Core CPU
> Ubuntu x64 14.04.1 LTS
> Xvfb Display
> 
> I tried to install precompiled Qt Libararies from the website (5.3.1).
> After I click on Next, it craches with Segmentation fault. Same with precompiled Qt-Creator.
> 
> I also tried to use pre build package from apt (5.2.1).
> but from this installation I could not start Qt-Creator (3.0.1).
> When I build from Source (5.3.1), Qt-Creator (3.2.0) is able to start but craches when I try to open a project.
> Interesting is that my project compiles and runs without any problems. Build Configuration: ./configure -developer-build -opensource -nomake examples -nomake tests -prefix /usr/local/Qt-5.3.1 -qt-xcb
> 
> I have read many topics but did not find a solution.
> It has probably something to do with memory allocation.
> 
> I was not able to debug qtcreator because gdb threw segmentation fault, too.
> Here is a gdb trace of the setup:
> 
> gdb qt-opensource-linux-x64-5.3.1.run
> GNU gdb (Ubuntu 7.7-0ubuntu3.1) 7.7
> This GDB was configured as “x86_64-linux-gnu”.
> Reading symbols from qt-opensource-linux-x64-5.3.1.run…(no debugging symbols found)…done.
> (gdb) run
> Starting program: /home/niels/qt/qt-opensource-linux-x64-5.3.1.run
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library “/lib/x86_64-linux-gnu/libthread_db.so.1”.
> [New Thread 0×7ffff3678700 (LWP 1913)]
> [New Thread 0×7ffff2bc1700 (LWP 1914)]
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0×0000000000662223 in QTJSC::ExecutablePool::systemAlloc(unsigned long) ()
> 
> (gdb) where
> #0 0×0000000000662223 in QTJSC::ExecutablePool::systemAlloc(unsigned long) ()
> #1 0×00000000006b02e3 in QTJSC::JSGlobalData::JSGlobalData(bool) ()
> #2 0×00000000006b0a6c in QTJSC::JSGlobalData::create() ()
> #3 0×0000000000611927 in QScriptEnginePrivate::QScriptEnginePrivate() ()
> #4 0×00000000006127fe in QScriptEngine::QScriptEngine(QObject*) ()
> #5 0×00000000004a9cb8 in QInstaller::ScriptEngine::ScriptEngine(QInstaller::PackageManagerCore*) ()
> #6 0×0000000000455d9c in QInstaller::PackageManagerCorePrivate::componentScriptEngine() const ()
> #7 0×000000000049a5f9 in QInstaller::Component::loadComponentScript(QString const&) ()
> #8 0×000000000049b9bc in QInstaller::Component::loadComponentScript() ()
> #9 0×0000000000468e66 in QInstaller::PackageManagerCorePrivate::buildComponentTree(QHash<QString, QInstaller::Component*>&, bool) ()
> #10 0×000000000044a62e in QInstaller::PackageManagerCore::fetchAllPackages(QList<KDUpdater::Update*> const&, QHash<QString, KDUpdater::PackageInfo> const&) ()
> #11 0×000000000045032e in QInstaller::PackageManagerCore::fetchRemotePackagesTree() ()
> #12 0×000000000042d0f1 in IntroductionPageImpl::validatePage() ()
> #13 0×0000000000d4a8c7 in QWizard::next() ()
> […]
> 
> last lines of strace qt-opensource-linux-x64-5.3.1.run
> mmap(NULL, 2147483648, PROT_READ|PROT_WRITE|PROT_EXEC,MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = -1 ENOMEM(Cannot allocate memory) —- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xbbadbeef} —-
> +++ killed by SIGSEGV (core dumped) +++
> 
> Why does it try to allocate 2GB memory ?
> 
> strace qtcreator (own build)
> […]
> stat(”/home/niels/qt/qt-creator-opensource-src-3.2.0/share/qtcreator/qml-type-descriptions/qbs-bundle.json”, {st_mode=S_IFREG|0644, st_size=305, …}) = 0
> open(”/home/niels/qt/qt-creator-opensource-src-3.2.0/share/qtcreator/qml-type-descriptions/qbs-bundle.json”, O_RDONLY|O_CLOEXEC) = 18
> fcntl(18, F_SETFD, FD_CLOEXEC) = 0
> fstat(18, {st_mode=S_IFREG|0644, st_size=305, …}) = 0
> fstat(18, {st_mode=S_IFREG|0644, st_size=305, …}) = 0
> fstat(18, {st_mode=S_IFREG|0644, st_size=305, …}) = 0
> read(18, “{\n \“name\”: \“qbs\”,\n \“search”…, 16384) = 305
> read(18, “”, 16079) = 0
> mmap(NULL, 2147483648, PROT_READ|PROT_WRITE|PROT_EXEC,MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = -1 ENOMEM(Cannot allocate memory)
> —- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xbbadbeef} —-
> +++ killed by SIGSEGV (core dumped) +++
> 
> Again 2GB ?
> 
> strace qtcreator (repository) [...] openat(AT_FDCWD, “/”, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 17statfs(”/”, {f_type=0×565a4653, f_bsize=4096, f_blocks=12500000, f_bfree=8499470, f_bavail=8499470, f_files=250000, f_ffree=61885, f_fsid={-1280375273, -1264953772}, f_namelen=255, f_frsize=4096}) = 0 getdents(17, /* 27 entries */, 32768) = 704 getdents(17, /* 0 entries */, 32768) = 0 close(17) = 0 openat(AT_FDCWD, “/qch”, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory) clock_gettime(CLOCK_MONOTONIC, {2608050, 303164993}) = 0 poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}]) writev(3, [{”\17\0\2\0\17\0\0\1”, 8}], 1) = 8 futex(0×200f0e8, FUTEX_WAKE_PRIVATE, 1) = 1 futex(0×7fff12a438c0, FUTEX_WAKE_PRIVATE, 1) = 1 futex(0×7fff12a438c4, FUTEX_WAIT_PRIVATE, 1, NULL) = -1 EAGAIN (Resource temporarily unavailable) futex(0×200f0e8, FUTEX_WAKE_PRIVATE, 1) = 0 write(5, “\1\0\0\0\0\0\0\0”, 8) = 8 write(5, “\1\0\0\0\0\0\0\0”, 8) = 8 —- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_ACCERR, si_addr=0×7f075044c000} —- +++ killed by SIGSEGV (core dumped) +++
> 
> I hope you can help me or at least provide a workaround for qtcreator.
> 
> Kind Regards Niels