ParallelSSH/ssh-python

Tests fail when using libssh master

adelton opened this issue · 4 comments

adelton commented

Hello,

when I build ssh-python against libssh master, test test_channel_exec fails.

In the https://github.com/ParallelSSH/ssh-python checkout directory I do

  • rm -rf libssh && git clone git://git.libssh.org/projects/libssh.git --depth 1
  • python3 setup.py build_ext --inplace
  • python3 setup.py test --test-suite tests.test_channel.ChannelTest

The output ends with

WARNING: 'UsePAM no' is not supported in Fedora and may cause several problems.
/root/ssh-python/tests/embedded_server/openssh.py:68: ResourceWarning: unclosed <socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 59326), raddr=('127.0.0.1', 2222)>
  del sock
ResourceWarning: Enable tracemalloc to get the object allocation traceback
test_channel_exec (tests.test_channel.ChannelTest) ... ERROR
test_close (tests.test_channel.ChannelTest) ... ok
test_exit_code (tests.test_channel.ChannelTest) ... ok
test_long_running_execute (tests.test_channel.ChannelTest) ... ok
test_pty (tests.test_channel.ChannelTest) ... ok
test_read_stderr (tests.test_channel.ChannelTest) ... ok

======================================================================
ERROR: test_channel_exec (tests.test_channel.ChannelTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/root/ssh-python/tests/test_channel.py", line 57, in test_channel_exec
    size, data = chan.read()
  File "ssh/channel.pyx", line 166, in ssh.channel.Channel.read
    return handle_ok_error_codes(rc), buf
  File "ssh/utils.pyx", line 74, in ssh.utils.handle_ok_error_codes
    raise SSHError
ssh.exceptions.SSHError

----------------------------------------------------------------------
Ran 6 tests in 3.834s

FAILED (errors=1)
Test failed: <unittest.runner.TextTestResult run=6 errors=1 failures=0>
error: Test failed: <unittest.runner.TextTestResult run=6 errors=1 failures=0>

All other tests pass.

This is on Fedora 29 with gcc-8.3.1-2.fc29.x86_64.

adelton commented

I tried to debug the failure a bit and it seems that the

rc = c_ssh.ssh_channel_read(self._channel, cbuf, size, is_stderr)

in ssh/channel.pyx returns -1 the second time it is called from tests/test_channel.py's test_channel_exec.

With the libssh/ content as shipped with ssh-python, the call returns 0 the second time it is called.

However, in my C-code which uses libssh, I still see 0 returned when I run ssh_channel_read after there is no more output -- so it seems like ssh-python sets something about the session or channel which causes the return to be -1.

adelton commented

I see the same test failure when I use the packaged libssh-0.8.7-1.fc29.x86_64 using

  • rm -rf libssh # to make sure we are not using the embedded code
  • SYSTEM_LIBSSH=1 python3 setup.py build_ext --inplace
  • SYSTEM_LIBSSH=1 python3 setup.py test --test-suite tests.test_channel.ChannelTest
pkittenis commented

Hi there,

Thanks for the interest.

Hm, that is interesting. -1 is SSH_ERROR, so the code is correct as far as I can see. Channel.read only returns code from ssh_channel_read so there is nothing else happening in bindings code. Will need to take a look at debug output.

pkittenis commented

Doesn't error with 0.9.4.