Description of problem: Client hangs when using default UDP client and server settings. This does not appear to be an upstream issue because if I build the package myself, this does not happen. Version-Release number of selected component (if applicable): iperf-2.0.13-5.fc33.x86_64 How reproducible: always Steps to Reproduce: 1. Start server using the command "iperf -s -u" 2. Start client using the command "iperf -c 127.0.0.1 -u" 3. Wait approximately 12 seconds Actual results: The client issues the warning "WARNING: did not receive ack of last datagram after 10 tries" and hangs until Ctrl-C is pressed. Expected results: The client should terminate normally with expected packet statistics. Additional info: This behavior is not seen if I build iperf myself from the same source package referenced in the spec file. This also was not seen in the f32 version, so it seems to have something to do with the way this package was built. I suspect it has to do with the size of signed integers, since a negative value is what the client uses to request the server send an ACK.
This issue is caused by https://fedoraproject.org/wiki/LTOByDefault Fedora 33 enabled LTO by default, and this somehow breaks iperf. Overriding the lto flags in the spec file fixes this issue. This one-line change to the spec file fixes it: diff --git a/iperf.spec b/iperf.spec index 6512a09..ceeec11 100644 --- a/iperf.spec +++ b/iperf.spec @@ -18,6 +18,7 @@ jitter, datagram loss. %patch0 -p1 %build +%define _lto_cflags %{nil} autoconf %configure %{__make} %{?_smp_mflags}
FEDORA-2020-11c341ca42 has been submitted as an update to Fedora 33. https://bodhi.fedoraproject.org/updates/FEDORA-2020-11c341ca42
FEDORA-2020-11c341ca42 has been pushed to the Fedora 33 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2020-11c341ca42` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2020-11c341ca42 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2020-11c341ca42 has been pushed to the Fedora 33 stable repository. If problem still persists, please make note of it in this bug report.