很长一段时间以来，我一直在开发一个名为 RoboJournal 的程序。最近有人给我发了一份错误报告，解释了在启用拼写检查功能时显示编辑器窗口表单时整个程序如何崩溃。但是，在程序设置中禁用拼写检查时，一切正常。这个错误似乎只影响特定版本的 Qt (4.8.3)，因为我已经在 4.7.4 和 4.8.4 上测试了该应用程序并且一切正常。在此之前我从未注意到这个错误，因为我没有在 4.8.3 上开发应用程序。这个错误是我还没有为 Debian 打包应用程序的主要原因；我计划在下一个版本中包含修复。
每当我遇到崩溃的错误时，我通常会通过调试器 (gdb) 运行代码，设置断点，然后逐行检查，直到找到问题所在。但是，这次我不能这样做，因为该错误仅影响发布版本；我尝试针对 Qt 4.8.3 调试库构建应用程序，但令我惊讶的是一切正常！显然，崩溃与该特定版本的 Qt 上的发布库有关，但我不知道它是什么。当遇到问题的唯一方法是发布版本时，如何正确调试应用程序？当我通过 gdb 运行它时，我尝试在发布版本上设置断点，但这不起作用。
幸运的是，这个错误似乎已经在 Qt 4.8.4 中得到修复（以及更新的版本，但我还没有在 Qt 5 上测试过），但我仍然需要为那些使用 4.8.3 的人找出一个解决方法。（我不能指望用户推出他们自己的 Qt，而且我不知道 Debian 人什么时候会用新版本更新他们的存储库）有什么想法吗？
这是崩溃的 gdb 输出。据我所知，该错误与 libc.so.6 有关：
buffer overflow detected ***: /usr/local/bin/robojournal terminated
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x5c)[0x7ffff44fb82c]
/lib/x86_64-linux-gnu/libc.so.6(+0x109700)[0x7ffff44fa700]
/usr/local/bin/robojournal[0x49982f]
/usr/local/bin/robojournal[0x49a374]
/usr/local/bin/robojournal[0x49b192]
/usr/local/bin/robojournal[0x49b6da]
/usr/local/bin/robojournal[0x4a947d]
/usr/local/bin/robojournal[0x432e17]
/usr/local/bin/robojournal[0x43529f]
/usr/local/bin/robojournal[0x421afb]
/usr/local/bin/robojournal[0x4ace7b]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN11QMetaObject8activateEP7QObjectPKS_iPPv+0x483)[0x7ffff5075123]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN15QAbstractButton7clickedEb+0x32)[0x7ffff5bee422]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x589d2e)[0x7ffff5941d2e]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x58a560)[0x7ffff5942560]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN15QAbstractButton17mouseReleaseEventEP11QMouseEvent+0x8c)[0x7ffff59427cc]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN11QToolButton17mouseReleaseEventEP11QMouseEvent+0xa)[0x7ffff59fc99a]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN7QWidget5eventEP6QEvent+0x7e0)[0x7ffff55d3850]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent+0xac)[0x7ffff5583e9c]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN12QApplication6notifyEP7QObjectP6QEvent+0x99b)[0x7ffff5588b6b]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN16QCoreApplication14notifyInternalEP7QObjectP6QEvent+0x8e)[0x7ffff505f56e]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN19QApplicationPrivate14sendMouseEventEP7QWidgetP11QMouseEventS1_S1_PS1_R8QPointerIS0_Eb+0x143)[0x7ffff5584cd3]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x24a554)[0x7ffff5602554]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN12QApplication15x11ProcessEventEP7_XEvent+0xd6f)[0x7ffff560144f]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x270fa2)[0x7ffff5628fa2]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x135)[0x7ffff296cab5]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x47de8)[0x7ffff296cde8]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_iteration+0x34)[0x7ffff296cea4]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE+0x66)[0x7ffff508dbf6]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x270c1e)[0x7ffff5628c1e]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN10QEventLoop13processEventsE6QFlagsINS_17ProcessEventsFlagEE+0x2f)[0x7ffff505e2bf]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE+0x138)[0x7ffff505e548]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN16QCoreApplication4execEv+0x88)[0x7ffff5063708]
/usr/local/bin/robojournal[0x412f34]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7ffff441276d]
/usr/local/bin/robojournal[0x413cc1]
======= Memory map: ========
00400000-005b0000 r-xp 00000000 08:01 48248 /usr/local/bin/robojournal
007af000-007b0000 r--p 001af000 08:01 48248 /usr/local/bin/robojournal
007b0000-007b5000 rw-p 001b0000 08:01 48248 /usr/local/bin/robojournal
007b5000-00eb3000 rw-p 00000000 00:00 0 [heap]
7fffdc000000-7fffdc021000 rw-p 00000000 00:00 0
7fffdc021000-7fffe0000000 ---p 00000000 00:00 0
7fffe16a0000-7fffe16a1000 ---p 00000000 00:00 0
7fffe16a1000-7fffe1ea1000 rw-p 00000000 00:00 0
7fffe1ea1000-7fffe215d000 r-xp 00000000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe215d000-7fffe235c000 ---p 002bc000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe235c000-7fffe2362000 r--p 002bb000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe2362000-7fffe23e0000 rw-p 002c1000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe23e0000-7fffe23e5000 rw-p 00000000 00:00 0
7fffe23e5000-7fffe23f5000 r-xp 00000000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe23f5000-7fffe25f5000 ---p 00010000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe25f5000-7fffe25f6000 r--p 00010000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe25f6000-7fffe25f7000 rw-p 00011000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe2648000-7fffe264c000 r-xp 00000000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe264c000-7fffe284c000 ---p 00004000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe284c000-7fffe284d000 r--p 00004000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe284d000-7fffe284e000 rw-p 00005000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe284e000-7fffe286a000 r--s 00000000 08:01 40509 /usr/share/mime/mime.cache
7fffe286b000-7fffe28cb000 rw-s 00000000 00:04 4620315 /SYSV00000000 (deleted)
7fffe28cb000-7fffe2afe000 rw-s 00000000 00:04 4587546 /SYSV00000000 (deleted)
7fffe2afe000-7fffe2ba3000 r--p 00000000 08:01 277820 /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans-Bold.ttf
7fffe2ba3000-7fffe2bae000 r-xp 00000000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2bae000-7fffe2dad000 ---p 0000b000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2dad000-7fffe2dae000 r--p 0000a000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2dae000-7fffe2db1000 rw-p 0000b000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2db1000-7fffe2e1e000 r-xp 00000000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe2e1e000-7fffe301e000 ---p 0006d000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe301e000-7fffe301f000 r--p 0006d000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe301f000-7fffe3022000 rw-p 0006e000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe3022000-7fffe3029000 r-xp 00000000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe3029000-7fffe3228000 ---p 00007000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe3228000-7fffe3229000 r--p 00006000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe3229000-7fffe322a000 rw-p 00007000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe322a000-7fffe322f000 r-xp 00000000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe322f000-7fffe342e000 ---p 00005000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe342e000-7fffe342f000 r--p 00004000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe342f000-7fffe3430000 rw-p 00005000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe3430000-7fffe3484000 r-xp 00000000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3484000-7fffe3683000 ---p 00054000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3683000-7fffe3685000 r--p 00053000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3685000-7fffe3686000 rw-p 00055000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3686000-7fffe368b000 r-xp 00000000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe368b000-7fffe388a000 ---p 00005000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe388a000-7fffe388b000 r--p 00004000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe388b000-7fffe388c000 rw-p 00005000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe388c000-7fffe38c1000 r-xp 00000000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe38c1000-7fffe3ac0000 ---p 00035000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe3ac0000-7fffe3ac1000 r--p 00034000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe3ac1000-7fffe3ac2000 rw-p 00035000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe3ac2000-7fffe3ac5000 rw-p 00000000 00:00 0
7fffe3ac5000-7fffe3b4f000 r-xp 00000000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3b4f000-7fffe3d4f000 ---p 0008a000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3d4f000-7fffe3d52000 r--p 0008a000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3d52000-7fffe3d54000 rw-p 0008d000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3d54000-7fffe3d59000 r-xp 00000000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3d59000-7fffe3f59000 ---p 00005000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3f59000-7fffe3f5a000 r--p 00005000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3f5a000-7fffe3f5b000 rw-p 00006000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3f5b000-7fffe3f9a000 r-xp 00000000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe3f9a000-7fffe419a000 ---p 0003f000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe419a000-7fffe419b000 r--p 0003f000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe419b000-7fffe419c000 rw-p 00040000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe419c000-7fffe41ac000 rw-p 00000000 00:00 0
7fffe41c2000-7fffe41c9000 r-xp 00000000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe41c9000-7fffe43c8000 ---p 00007000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe43c8000-7fffe43c9000 r--p 00006000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe43c9000-7fffe43ca000 rw-p 00007000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe43ca000-7fffe43d1000 r-xp 00000000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe43d1000-7fffe45d0000 ---p 00007000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe45d0000-7fffe45d1000 r--p 00006000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe45d1000-7fffe45d2000 rw-p 00007000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe45d2000-7fffe45d9000 r-xp 00000000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe45d9000-7fffe47d8000 ---p 00007000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe47d8000-7fffe47d9000 r--p 00006000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe47d9000-7fffe47da000 rw-p 00007000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe47da000-7fffe47dc000 r-xp 00000000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe47dc000-7fffe49db000 ---p 00002000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe49db000-7fffe49dc000 r--p 00001000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe49dc000-7fffe49dd000 rw-p 00002000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe49dd000-7fffe49e6000 r-xp 00000000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe49e6000-7fffe4be6000 ---p 00009000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe4be6000-7fffe4be7000 r--p 00009000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe4be7000-7fffe4be8000 rw-p 0000a000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe4be8000-7fffe4c17000 r-xp 00000000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4c17000-7fffe4e17000 ---p 0002f000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4e17000-7fffe4e18000 r--p 0002f000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4e18000-7fffe4e19000 rw-p 00030000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4e19000-7fffe4e25000 r-xp 00000000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
7fffe4e25000-7fffe5024000 ---p 0000c000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
7fffe5024000-7fffe5025000 r--p 0000b000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
7fffe5025000-7fffe5026000 rw-p 0000c000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
Program received signal SIGABRT, Aborted.
0x00007ffff4427425 in raise () from /lib/x86_64-linux-gnu/libc.so.6