Caveat: I know this is probably an upstream bug so I'm just looking for some general info. This is my first try at debugging. I'm using the wiki articles for my guidance. I some questions about debugging a KDE app, kshisen which is included in the kdeames package. The best I can describe the behavior is "it hangs at random intervals. Either when you select a tile it takes several seconds to highlight it, after the first selection the matching selection takes 5 to 10 seconds, then continues without crashing". I've tried to get a screenshot but an unable to when kshisen is hung up. I've recompiled the dependencies and kshisen like this and built the packages in a clean chroot with extra-x86_64-build. options=('!strip') build() { export CFLAGS="-fbuiltin -g -march=native -O1 -pipe -fstack-protector-all --param=ssp-buffer-size=4 -D_FORTIFY_SOURCE=2" export CXXFLAGS="-fbuiltin -g -march=native -O1 -pipe -fstack-protector-all --param=ssp-buffer-size=4 -D_FORTIFY_SOURCE=2" export LDFLAGS="-Wl,-O1,--sort-common,--as-needed,-z,relro,--hash-style=gnu" cd $srcdir mkdir build cd build cmake ../../${pkgbase}-${pkgver} -DCMAKE_BUILD_TYPE=Debug -DCMAKE_SKIP_RPATH=ON -DCMAKE_INSTALL_PREFIX=/usr -DPYTHON_EXECUTABLE=/usr/bin/python2 make } Next I ran [ valgrind --leak-check=full --track-origins=yes --time-stamp=yes /usr/bin/kshisen ]. Valgrind reports several memory leaks. As an example: ==00:00:07:20.414 32628== 24 bytes in 1 blocks are definitely lost in loss record 139 of 425 ==00:00:07:20.414 32628== at 0x4C2993D: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==00:00:07:20.414 32628== by 0xBA3A75A: FcPatternCreate (in /usr/lib/libfontconfig.so.1.4.4) ==00:00:07:20.414 32628== by 0xBA3861D: FcFontRenderPrepare (in /usr/lib/libfontconfig.so.1.4.4) ==00:00:07:20.414 32628== by 0xBA3883C: FcFontMatch (in /usr/lib/libfontconfig.so.1.4.4) ==00:00:07:20.414 32628== by 0x60BB2D7: QFontDatabase::load(QFontPrivate const*, int) (in /usr/lib/libQtGui.so.4.8.0) ==00:00:07:20.414 32628== by 0x6098586: QFontPrivate::engineForScript(int) const (in /usr/lib/libQtGui.so.4.8.0) ==00:00:07:20.414 32628== by 0x60AC187: QFontMetrics::height() const (in /usr/lib/libQtGui.so.4.8.0) ==00:00:07:20.414 32628== by 0x62E1949: QStatusBar::reformat() (in /usr/lib/libQtGui.so.4.8.0) ==00:00:07:20.414 32628== by 0x62E1C59: QStatusBar::setSizeGripEnabled(bool) (in /usr/lib/libQtGui.so.4.8.0) ==00:00:07:20.414 32628== by 0x62E2007: QStatusBar::QStatusBar(QWidget*) (in /usr/lib/libQtGui.so.4.8.0) ==00:00:07:20.414 32628== by 0x515E55D: KStatusBar::KStatusBar(QWidget*) (in /usr/lib/libkdeui.so.5.8.0) ==00:00:07:20.414 32628== by 0x513F989: KMainWindow::statusBar() (in /usr/lib/libkdeui.so.5.8.0) Next I ran [ strace -eopen /usr/bin/kshisen ], which spits out quite a few missing/not found files. As and example: open("/usr/lib/tls/x86_64/libjson.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/tls/libjson.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/x86_64/libjson.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) There is no directory /usr/lib/tls. Then I ran [ readelf -a /usr/bin/kshisen | grep interp ] with the following results. [ 1] .interp PROGBITS 0000000000400238 00000238 [Requesting program interpreter: /lib/ld-linux-x86-64.so.2] 01 .interp 02 .interp .note.ABI-tag .note.gnu.build-id .gnu.hash .dynsym .dynstr .gnu.version .gnu.version_r .rela.dyn .rela.plt .init .plt .text .fini .rodata .eh_frame_hdr .eh_frame Then I ran [ LD_DEBUG=files /usr/bin/kshisen > kshisen-lddebug.log 2>&1 ] which produces a long log. If it would help I can put all the files in a pastebin. I may be into overload but was trying to have enough info up front. First question. Would a backtrace do any good? Second question (sort of). I would like to bisect this app by cloning the svn repo then compiling a previous version. Will I (my belief is yes) need to set up a virtual environment to work on say the 4.7.9 version? Any help or suggestions would be appreciated. Myra -- Life's fun when your sick and psychotic!