[armhf] learning switch - OpenFlow15 test fails due to unexpected debug logging

Open vSwitch 3.2.0 added the ability to print backtraces in the event of a fatal crash. The commit [0] adding this functionality also added debug logging on startup if a call to libc backtrace() does not provide any frames.

On the systems where armhf packages are built and tested this is the case and as a consequence the build fails.

Test log excerpt:
# -*- compilation -*-
2560. learning-switch.at:7: testing learning switch - OpenFlow15 ...
../../tests/learning-switch.at:9: ovs-testcontroller --no-chdir --detach punix:controller --pidfile -v ptcp:
--- /dev/null 2023-08-22 06:47:35.672268660 +0000
+++ /tmp/openvswitch-3.2.0/_debian/tests/testsuite.dir/at-groups/2560/stderr 2023-08-22 07:45:45.858016173 +0000
@@ -0,0 +1 @@
+2023-08-22T07:45:45Z|00001|fatal_signal|DBG|Capturing of dummy backtrace has failed.
stdout:
2560. learning-switch.at:7: 2560. learning switch - OpenFlow15 (learning-switch.at:7): FAILED (learning-switch.at:9)

Compiling and running this super simple program confirms the behavior in isolation:
#include <stdio.h>

#include <execinfo.h>

#define BACKTRACE_MAX_FRAMES 31

int
main(int argc, char **argv)
{
    int n_frames;
    void *frames[BACKTRACE_MAX_FRAMES];

    n_frames = backtrace(frames, BACKTRACE_MAX_FRAMES);

    printf("%d/%d", n_frames, BACKTRACE_MAX_FRAMES);
}

0: https://github.com/openvswitch/ovs/commit/759a29dc2d97bfba9e3c5270a621beca673962ca