Could not load network backend on embedded Linux system

Shen sida

Hi all

I found the the network backend could not be loaded on embedded Linux system. But the library file could be found.

BTW, it could be loaded on Windows and desktop Linux (Ubuntu).

Embedded system information as follow:
Yocto Linux 5.15, with Qt 6.4.2

Let me know if you want to get more details.

Best regards

SGaist

Hi,

Did you check with ldd whether all the plugins dependencies are present ?

Shen sida

@SGaist said in Could not load network backend on embedded Linux system:

Did you check with ldd whether all the plugins dependencies are present ?

Here is the output of ldd /usr/lib/plugins/networkmanager/libqnetworkmanager.so

Looks like all dependencies are present.

Let me know if you need other information.

SGaist

How did you install Qt on the target ?

JoeCFD

@Shen-sida run
strace your_app
to check what is missing or wrong?

Shen sida

@SGaist Did you mean how to compile a whole image with Qt?

It's based on Yocto project 5.15 for imx6.

Shen sida

@JoeCFD So many mesaages after running this command. How to check them?

JoeCFD

@Shen-sida
redirect output to a file:
strace -o log.txt your app

Shen sida

@JoeCFD but I couldn't send the file here :( .

SGaist

What issue did you have ?

JoeCFD

@Shen-sida you can show only the part here which displays loading failure. You can find out in the file which dependency lib is unable to be loaded.

Shen sida

@JoeCFD If about network, here is the information:

openat(AT_FDCWD, "/usr/lib/libQt6Network.so.6", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\3\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\0\0\0\0004\0\0\0"..., 512) = 512
statx(3, "", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT|AT_EMPTY_PATH, STATX_BASIC_STATS, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0755, stx_size=1178928, ...}) = 0
mmap2(NULL, 1309948, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x76780000
mmap2(0x76780000, 1244412, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0) = 0x76780000
munmap(0x768b0000, 64764)               = 0
mprotect(0x76899000, 61440, PROT_NONE)  = 0
mmap2(0x768a8000, 32768, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x118000) = 0x768a8000
close(3)                                = 0

Shen sida

@SGaist
The project couldn't load the network manager module.
I want to get network information such as IP address from it.
I have tested on desktop Windows and Linux, it works well. But on embedded Linux it doesn't work.

JoeCFD

@Shen-sida there is no message to tell loading fails. In your first post, loading libqnetworkmanager failed. Here you showed message for a different lib. You are looking at the wrong spot. Have you ever installed another version of Qt6? If you can use synaptic, open it to check all Qt libs(plus plugins) have the same versions. You can click the property of any lib to find out where they are located.