Incompatible libpng version in application and library

[Tom asso]

My QtQuick application previously worked with Qt 5.12 and Ubuntu 16.04. Since then I've updated to Qt 5.13.0 and Ubuntu 18.04.03, and now the app segfaults when opening a file dialog:

libpng warning: Application jmp_buf size changed

Thread 1 "mbgrdviz" received signal SIGSEGV, Segmentation fault.
__longjmp_chk (env=0x0, val=1) at ../setjmp/longjmp.c:32
32	../setjmp/longjmp.c: No such file or directory.
(gdb) bt
#0  0x00007ffff4e43b00 in __longjmp_chk (env=0x0, val=1)
    at ../setjmp/longjmp.c:32
#1  0x00007fffb423bc9c in  ()
    at /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
#2  0x00007ffff08492c7 in png_error (png_ptr=0x555557fe6ad0, error_message=error_message@entry=0x7ffff0dd9cb8 "Incompatible libpng version in application and library") at libpng/pngerror.c:80
#3  0x00007ffff084c685 in png_create_read_struct_2 (user_png_ver=0x7fffb423ce57 "1.6.34", error_ptr=0x555557fd11a0, error_fn=0x7fffb423bc50, warn_fn=0x7fffb423cd10, mem_ptr=0x0, malloc_fn=0x7fffb423c320, free_fn=0x7fffb423afc0)
    at libpng/pngread.c:150

I've installed libpng16 on my system. I rebuilt Qt5.13.0 after configuring it to use the system libpng:

./configure -system-libpng
make 
make install

I've cleaned and rebuilt my app after these steps but still get the same segfault due to "Incompatible libpng version in application and library".
Suggested fixes?
I am building with qtcreator 4.11.1 - how can see exactly what libpng files it's compiling with and which libpng.so it's liking with?

Thanks
Tom

[SGaist]

Hi,

Are you using any external library with your application that also makes use if libpng ?

[Tom asso]

@SGaist - hm, I am linking with numerous third-party .so libraries. What is the best way to determine their possible dependence on libpng? Thanks!

[Christian Ehrlicher]

ldd is your friend

[Tom asso]

@Christian-Ehrlicher - 'ldd myprog | grep libpng' does not show any result, so I assume that means myprog doesn't rely on libpng dynamic library. What else should I check? Thanks!

[SGaist]

You should check all the third party libraries you are using.

[Tom asso]

@SGaist - Thanks - what tool should I use to check these libraries?

[SGaist]

The same tool: ldd

[Tom asso]

@SGaist - Hm, checked all of them with ldd - none show 'libpng*' in the list

[SGaist]

Any of these uses plugins ?

[Tom asso]

@SGaist - I do not think so, at least I didn't create any. To be sure I ran 'ldd -u -d -r ' on all *plugin.so files in my Qt5.13.0 directory, none of them show dependency on libpng.
Obviously something is invoking libpng routines, but I haven't found libpng dependency with ldd in any of my app's libraries....???

[SGaist]

Can you provide a full stack trace of your crash ?

[Tom asso]

@SGaist - yes, gdb stacktrace is below - thank you!

Thread 1 "mbgrdviz" received signal SIGSEGV, Segmentation fault.
__longjmp_chk (env=0x0, val=1) at ../setjmp/longjmp.c:32
32	../setjmp/longjmp.c: No such file or directory.
(gdb) bt
#0  0x00007ffff4e43b00 in __longjmp_chk (env=0x0, val=1)
    at ../setjmp/longjmp.c:32
#1  0x00007fffb423bc9c in  ()
    at /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
#2  0x00007ffff08492c7 in png_error (png_ptr=0x555557fde4f0, error_message=error_message@entry=0x7ffff0dd9cb8 "Incompatible libpng version in application and library") at libpng/pngerror.c:80
#3  0x00007ffff084c685 in png_create_read_struct_2 (user_png_ver=0x7fffb423ce57 "1.6.34", error_ptr=0x555557faf050, error_fn=0x7fffb423bc50, warn_fn=0x7fffb423cd10, mem_ptr=0x0, malloc_fn=0x7fffb423c320, free_fn=0x7fffb423afc0)
    at libpng/pngread.c:150
#4  0x00007fffb423befb in  ()
    at /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
#5  0x00007fffe07a408c in  ()
    at /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#6  0x00007fffe07a4955 in gdk_pixbuf_loader_close ()
    at /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#7  0x00007fffe07a120b in  ()
    at /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#8  0x00007fffe07a223c in gdk_pixbuf_new_from_stream ()
    at /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#9  0x00007fffe15ff142 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#10 0x00007fffe15ff2bb in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#11 0x00007fffe15ffb46 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#12 0x00007fffe15f74b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#13 0x00007fffe172db3a in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#14 0x00007fffe15f5faa in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#15 0x00007fffe15aebf1 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#16 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#17 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#18 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#19 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#20 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#21 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#22 0x00007fffe159fcf4 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#23 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#24 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#25 0x00007fffe15a2601 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#26 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#27 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#28 0x00007fffe175b1c0 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#29 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#30 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#31 0x00007fffe175ad35 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#32 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#33 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#34 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#35 0x00007fffe159fcf4 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#36 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#37 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#38 0x00007fffe15a2601 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#39 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#40 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#41 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#42 0x00007fffe172ffd7 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#43 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#44 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#45 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#46 0x00007fffe159fcf4 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#47 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#48 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#49 0x00007fffe15a2601 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#50 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#51 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#52 0x00007fffe16ed820 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#53 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#54 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#55 0x00007fffe16ed6c1 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#56 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#57 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#58 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#59 0x00007fffe159fcf4 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#60 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#61 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#62 0x00007fffe15a2601 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#63 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#64 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#65 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#66 0x00007fffe159fcf4 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#67 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#68 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#69 0x00007fffe15a2601 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#70 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#71 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#72 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#73 0x00007fffe159fcf4 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#74 0x00007fffe15f140d in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#75 0x00007fffe15f6063 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#76 0x00007fffe15a2601 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#77 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#78 0x00007fffe15ec3ca in gtk_container_propagate_draw ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#79 0x00007fffe15ec4b2 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#80 0x00007fffe18136ef in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#81 0x00007fffe18058db in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#82 0x00007fffe180e998 in  () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#83 0x00007fffe16b2859 in gtk_main_do_event ()
    at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#84 0x00007fffe11c3765 in  () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#85 0x00007fffe11d37f5 in  () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#86 0x00007fffe11d49f6 in  () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#87 0x00007fffe11d4bf0 in  () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#88 0x00007fffdbdbc10d in g_closure_invoke ()
    at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#89 0x00007fffdbdcf05e in  () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#90 0x00007fffdbdd7715 in g_signal_emit_valist ()
    at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#91 0x00007fffdbdd812f in g_signal_emit ()
    at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#92 0x00007fffe11ccac9 in  () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#93 0x00007fffe11b8080 in  () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#94 0x00007fffeca4ed03 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#95 0x00007fffeca4e285 in g_main_context_dispatch ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#96 0x00007fffeca4e650 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#97 0x00007fffeca4e6dc in g_main_context_iteration ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#98 0x00007ffff5d7118f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x5555559fc4b0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#99 0x00007ffff5d17902 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fffffffda70, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:225
#100 0x00007ffff5d20260 in QCoreApplication::exec() ()
    at kernel/qcoreapplication.cpp:1373
#101 0x000055555555a767 in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at main.cpp:66

[SGaist]

Can you start your application with the QT_DEBUG_PLUGINS environment variable set 1 ?

[Tom asso]

@SGaist - Thank you. I do that and output shows multiple image libraries being loaded:

loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqgif.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqicns.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqico.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqjpeg.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqsvg.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqtga.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqtiff.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqwbmp.so"
loaded library "/home/oreilly/Qt/5.13.0/gcc_64/plugins/imageformats/libqwebp.so"

However these do not include libpng.so - probably because before building Qt I configured it to use my system's libpng; "./configure -system-libpng", while is libpng16. What else might the problem be?

[SGaist]

What QPA and theme plugins gets loaded ?

[Tom asso]

@SGaist - Thanks very much for your help!
I discovered which library is causing the problem. It's a non-Qt library that doesn't directly rely on libpng, but it does rely on 50+ other libraries - apparently one of those does directly or indirectly rely on libpng. Apparently ldd doesn't show recursive dependencies, which surprises me. https://stackoverflow.com/questions/15064685/does-ldd-also-show-dependencies-of-dependencies/15064784#15064784

[SGaist]

What library was it ?

[Tom asso]

@SGaist - the segfault occurs when I link with /usr/local/lib/libgmt.so.6.0.0, for the Generic Mapping Tools. I built the library from source and installed on this system. Yet when I run 'ldd /usr/local/lib/libgmt.so.6.0.0' it does not display any dependency on libpng - I don't understand why...

[Tom asso]

@SGaist - also tried installing libgmt-dev (rather than building myself) - I get the same segfault due to "Incompatible libpng version in application and library"