qa: Failure in `p2p_fingerprint.py` #34331

On FreeBSD 15.0, https://github.com/hebasto/bitcoin-core-nightly/actions/runs/21105606197/job/60696569283:

386/456 - p2p_fingerprint.py failed, Duration: 0 s

stdout:
2026-01-18T04:34:49.101209Z TestFramework (INFO): PRNG seed is: 4679507874993432966
2026-01-18T04:34:49.102528Z TestFramework (INFO): Initializing test directory /tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63
2026-01-18T04:34:49.360239Z TestFramework (ERROR): Unexpected exception
Traceback (most recent call last):
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 138, in main
    self.setup()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 269, in setup
    self.setup_network()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 360, in setup_network
    self.setup_nodes()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 382, in setup_nodes
    self.start_nodes()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 528, in start_nodes
    node.wait_for_rpc_connection()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_node.py", line 316, in wait_for_rpc_connection
    raise FailedToStartError(self._node_msg(
test_framework.test_node.FailedToStartError: [node 0] bitcoind exited with status 1 during initialization. Error: Unable to bind to 127.0.0.1:11756 on this computer. Bitcoin Core is probably already running.
Error: Failed to listen on any port. Use -listen=0 if you want this.
************************

2026-01-18T04:34:49.423831Z TestFramework (INFO): Not stopping nodes as test failed. The dangling processes will be cleaned up later.
2026-01-18T04:34:49.424142Z TestFramework (WARNING): Not cleaning up dir /tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63
2026-01-18T04:34:49.424336Z TestFramework (ERROR): Test failed. Test logging available at /tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63/test_framework.log
2026-01-18T04:34:49.424671Z TestFramework (ERROR): 
2026-01-18T04:34:49.425017Z TestFramework (ERROR): Hint: Call /home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/combine_logs.py '/tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63' to consolidate all logs
2026-01-18T04:34:49.425220Z TestFramework (ERROR): 
2026-01-18T04:34:49.425516Z TestFramework (ERROR): If this failure happened unexpectedly or intermittently, please file a bug and provide a link or upload of the combined log.
2026-01-18T04:34:49.425685Z TestFramework (ERROR): https://github.com/bitcoin/bitcoin/issues
2026-01-18T04:34:49.425795Z TestFramework (ERROR): 

From the netinet/in.h:

/*
 * Local port number conventions:
 *
 * When a user does a bind(2) or connect(2) with a port number of zero,
 * a non-conflicting local port address is chosen.
 * The default range is IPPORT_HIFIRSTAUTO through
 * IPPORT_HILASTAUTO, although that is settable by sysctl.
 *
 * A user may set the IPPROTO_IP option IP_PORTRANGE to change this
 * default assignment range.
 *
 * The value IP_PORTRANGE_DEFAULT causes the default behavior.
 *
 * The value IP_PORTRANGE_HIGH changes the range of candidate port numbers
 * into the "high" range.  These are reserved for client outbound connections
 * which do not want to be filtered by any firewalls.
 *
 * The value IP_PORTRANGE_LOW changes the range to the "low" are
 * that is (by convention) restricted to privileged processes.  This
 * convention is based on "vouchsafe" principles only.  It is only secure
 * if you trust the remote host to restrict these ports.
 *
 * The default range of ports and the high range can be changed by
 * sysctl(3).  (net.inet.ip.portrange.{hi,low,}{first,last})
 *
 * Changing those values has bad security implications if you are
 * using a stateless firewall that is allowing packets outside of that
 * range in order to allow transparent outgoing connections.
 *
 * Such a firewall configuration will generally depend on the use of these
 * default values.  If you change them, you may find your Security
 * Administrator looking for you with a heavy object.
 *
 * For a slightly more orthodox text view on this:
 *
 *            ftp://ftp.isi.edu/in-notes/iana/assignments/port-numbers
 *
 *    port numbers are divided into three ranges:
 *
 *                0 -  1023 Well Known Ports
 *             1024 - 49151 Registered Ports
 *            49152 - 65535 Dynamic and/or Private Ports
 *
 */

/*
 * Ports < IPPORT_RESERVED are reserved for
 * privileged processes (e.g. root).         (IP_PORTRANGE_LOW)
 */
#define	IPPORT_RESERVED		1024

/*
 * Default local port range, used by IP_PORTRANGE_DEFAULT
 */
#define IPPORT_EPHEMERALFIRST	10000
#define IPPORT_EPHEMERALLAST	65535

/*
 * Dynamic port range, used by IP_PORTRANGE_HIGH.
 */
#define	IPPORT_HIFIRSTAUTO	49152
#define	IPPORT_HILASTAUTO	65535

So I guess this may have been broken after #34186?

Yes, possibly. FreeBSD’s ephemeral port range (10000–65535) overlaps with the test framework’s static port range (11000–26000). Setting TEST_RUNNER_PORT_MIN=2000 in the external bitcoin-core-nightly FreeBSD CI workflow should mitigate this.

An alternative could be to set IP_PORTRANGE_HIGH, but I don't know how to do this on freebsd.

cc @vasild

A suggestion: https://github.com/bitcoin/bitcoin/pull/34336

Is it correct that the failing test p2p_fingerprint.py (ran as 386/456) is not using port=0 which was introduced in #34186?

So, it is probably because feature_proxy.py (280/456) ran before it and used port 11756 and left it in TIME_WAIT state (p2p_private_broadcast.py was 398/456 and feature_anchors.py was 425/456, after the failure of p2p_fingerprint.py), right?

So, it is probably because feature_proxy.py (280/456) ran before it and used port 11756 and left it in TIME_WAIT state (p2p_private_broadcast.py was 398/456 and feature_anchors.py was 425/456, after the failure of p2p_fingerprint.py), right?

Ah, good observation. I'd presume that the port was still in use, but it being in TIME_WAIT sounds plausible.

root# sysctl net.inet.ip.portrange.first=32768

Setting TEST_RUNNER_PORT_MIN=2000 ...

I think if this only affects freebsd, and all freebsd people are fine to use one of the workarounds, this seems fine. However, I think ideally the tests work out of the box as-is.

ideally the tests work out of the box as-is.

Updated the solution in #34346 to cover IPv6 sockets used by feature_proxy.py.

Another test resulted in seemingly the same error.

386/456 - p2p_fingerprint.py failed, Duration: 0 s

stdout:
2026-01-18T04:34:49.101209Z TestFramework (INFO): PRNG seed is: 4679507874993432966
2026-01-18T04:34:49.102528Z TestFramework (INFO): Initializing test directory /tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63
2026-01-18T04:34:49.360239Z TestFramework (ERROR): Unexpected exception
Traceback (most recent call last):
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 138, in main
    self.setup()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 269, in setup
    self.setup_network()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 360, in setup_network
    self.setup_nodes()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 382, in setup_nodes
    self.start_nodes()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_framework.py", line 528, in start_nodes
    node.wait_for_rpc_connection()
  File "/home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/test_framework/test_node.py", line 316, in wait_for_rpc_connection
    raise FailedToStartError(self._node_msg(
test_framework.test_node.FailedToStartError: [node 0] bitcoind exited with status 1 during initialization. Error: Unable to bind to 127.0.0.1:11756 on this computer. Bitcoin Core is probably already running.
Error: Failed to listen on any port. Use -listen=0 if you want this.
************************

2026-01-18T04:34:49.423831Z TestFramework (INFO): Not stopping nodes as test failed. The dangling processes will be cleaned up later.
2026-01-18T04:34:49.424142Z TestFramework (WARNING): Not cleaning up dir /tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63
2026-01-18T04:34:49.424336Z TestFramework (ERROR): Test failed. Test logging available at /tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63/test_framework.log
2026-01-18T04:34:49.424671Z TestFramework (ERROR): 
2026-01-18T04:34:49.425017Z TestFramework (ERROR): Hint: Call /home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/test/functional/combine_logs.py '/tmp/test_runner_₿_🏃_20260118_042715/p2p_fingerprint_63' to consolidate all logs
2026-01-18T04:34:49.425220Z TestFramework (ERROR): 
2026-01-18T04:34:49.425516Z TestFramework (ERROR): If this failure happened unexpectedly or intermittently, please file a bug and provide a link or upload of the combined log.
2026-01-18T04:34:49.425685Z TestFramework (ERROR): https://github.com/bitcoin/bitcoin/issues
2026-01-18T04:34:49.425795Z TestFramework (ERROR): 

With or without #34346 ?

With or without #34346 ?

The master branch.