Build failure: civetweb/http_server with target blackpill_f411ce and CONFIG_DEBUG=y

[Coi-l]

Describe the bug
Building http_server for board blackpill_f411ce and CONFIG_DEBUG=y fails

To Reproduce
Steps to reproduce the behavior:

west build -p auto -b blackpill_f411ce zephyr/samples/net/civetweb/http_server/ -- -DCONFIG_DEBUG=y

Expected behavior
Build succeded

Impact
It's would be nice with debug output.

Logs and console output

/home/xxx/toolchains/zephyr-sdk-0.14.1/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/10.3.0/../../../../arm-zephyr-eabi/bin/ld.bfd: modules/civetweb/lib..__modules__lib__civetweb.a(civetweb.c.obj): in function `pull_inner':
/home/xxx/Projects/zephyrproject/modules/lib/civetweb/src/civetweb.c:6426: undefined reference to `fileno'
/home/xxx/toolchains/zephyr-sdk-0.14.1/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/10.3.0/../../../../arm-zephyr-eabi/bin/ld.bfd: modules/civetweb/lib..__modules__lib__civetweb.a(civetweb.c.obj): in function `push_inner':
/home/xxx/Projects/zephyrproject/modules/lib/civetweb/src/civetweb.c:6267: undefined reference to `ferror'

Environment (please complete the following information):

• OS: Linux
• Toolchain: Zephyr SDK,
• Commit SHA or Version used:
  zephyr: 47850a3

Additional context
Seems related to this issue:
#36796
But the same fix does not seem to work (I think)

[erwango]

@rlubos Would you mind having a look? Seems this issue is not STM32 specific but rather linked to sample configuration.

[rlubos]

Well, the problem seems to be limited POSIX support in Zephyr. Civetweb is highly dependent on POSIX, and Zephyr does not make any guarantees on full POSIX support. Apparently enabling debug mode add addtional dependency to FS functionalities in Civetweb. Note that neither fileno() nor ferror() are supported by Zephyr.

You may try to implement them as a part of already existing POSIX extensions for CivetWeb, I think however this should rather be tracked as an enhancement, not a bug.

[rlubos]

Civetweb is no longer maintained in Zephyr, see #46746 for more details.