bash – Using systemd services to launch programs at boot, can view topics/nodes but can’t subscribe

I have a master(Ubuntu18.04+Melodic on Jetson Nano) and slave(Ubuntu 16.04+Kinetic on PC) conected properly. I am able to run ros nodes and have full duplex without any issues when these nodes are launched via terminal.

However, I want to start these nodes on bootup on the master, which I am trying to achieve by creating service. When I run the service, the nodes launch fine and I can echo topics receive messages just fine. However, when I try to echo topics on the slave PC, I get no messages. I am still able to view the topics list and publish to these topics, but can’t receive/echo messages in any topics.

When I run roswtf on PC, I get following errors:

ERROR: Unknown host (ubuntu) for node (/basefootprint_to_laser_broadcaster)
ERROR Could not contact the following nodes: (with all the node names below it)
ERROR The following nodes should be connected but aren't: (with all the node names below it)
ERROR Errors connecting to the following services: (with all service names below)
 * service (/basefootprint_to_laser_broadcaster/set_logger_level) appears to be malfunctioning: Unable to communicate with service (/basefootprint_to_laser_broadcaster/set_logger_level), address (rosrpc://ubuntu:49211)

Posting service and related bash file:

roscore.service (this is same as used by Ubiquity robotics, except that I swapped kinetic by melodic:

# Start roscore as a fork and then wait for the tcp port to be opened
# ----------------------------------------------------------------
# Source all the environment variables, start roscore in a fork
# Since the service type is forking, systemd doesn't mark it as
# 'started' until the original process exits, so we have the 
# non-forked shell wait until it can connect to the tcp opened by
# roscore, and then exit, preventing conflicts with dependant services
ExecStart=/bin/sh -c ". /opt/ros/melodic/; . ~/catkin_ws/devel/; roscore & while ! echo exit | nc localhost 11311 > /dev/null; do sleep 1; done"


Description=Mybot Minimal



# trial upstart script
sleep 1
source /opt/ros/melodic/setup.bash
source ~/catkin_ws/devel/setup.bash
roslaunch my_pkg minimal.launch

As per comment of a user on, it doesn’t work even when both devices are Melodic, so I don’t think the difference ROS versions are causing the issue.
I tried asking it on but nothing helped(link to that question).
I was told on stackoverflow to ask here. Hope this is not offtopic here.
Any help would be much appreciated, thanks!

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Thunar doesn’t launch in text editor from share

I recently updated to Ubuntu minimal 20.04.

In Thunar, if I right click a text file and select Open With Geany, it opens the file in Geany.
If I do the same thing with a text file on a shared drive, it doesn’t. I just get an empty Geany.

This worked before the update.

Is there a trick to make this work again?

Can we launch a deployment in Kubernetes with time limit if not then is any alternative available?

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When I want to edit the quick start navigation menu, before I was able to drag the menu and change it using “Edit Links”. Now, when I click on edit opens a new page that goes to the navigation settings. How can I fix this? will it be my features? And when I click a subpage I can’t see the other subpagesenter image description here – Earn upto $70 for 10k views + Launch bonus

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When I SSH into my development VM and want to open something in VSCode, I cannot do so from the command line. Obviously that makes sense because the code command runs on the remote server which has no idea about the host.

When running code from a VSCode integrated terminal using the SSH plugin will however open another VSCode window for that remote folder.

Is it possible to run a command (like code ./foldername) on my SSH connection and have that command do something on the host (e.g. open VSCode)? From a normal terminal window over SSH? Does such a thing exist?

macos – Unable to launch Firefox using Selenium

I installed Python 3.8 on MacOS Mojave (10.14.6) using pyenv. I then installed selenium. There was an issue missing the geckodriver. I then installed the geckodriver. After that I ran the program.


`import unittest
from import expected_conditions
from selenium import webdriver
from import WebDriverWait

class GoogleSearch(unittest.TestCase):
def setUp(self):
self.driver = webdriver.Firefox()
self.base_url = “”

def test_google_search(self):
    driver = self.driver

    element = driver.find_element_by_idname("q")
    element.send_keys("Selenium testing tools cookbook")

    WebDriverWait(driver, 30)
        .until(expected_conditions.title_contains("Selenium testing tools cookbook"))
    self.assertEqual(driver.title, "Selenium testing tools cookbook - Google Search")

def tearDown(self):

if name == “main“:
unittest.main(verbosity=2, warnings=”ignore”)`

I then get the following error message:
Manus-iMac:chapter01 Manu$ cat err1.dat
test_google_search (main.GoogleSearch) … ERROR

ERROR: test_google_search (main.GoogleSearch)

Traceback (most recent call last):
File “”, line 9, in setUp
self.driver = webdriver.Firefox()

File “/Users/Manu/.pyenv/versions/3.8.7/lib/python3.8/site-packages/selenium/webdriver/firefox/”, line 170, in init

File “/Users/Manu/.pyenv/versions/3.8.7/lib/python3.8/site-packages/selenium/webdriver/remote/”, line 157, in init
self.start_session(capabilities, browser_profile)

File “/Users/Manu/.pyenv/versions/3.8.7/lib/python3.8/site-packages/selenium/webdriver/remote/”, line 252, in start_session
response = self.execute(Command.NEW_SESSION, parameters)

File “/Users/Manu/.pyenv/versions/3.8.7/lib/python3.8/site-packages/selenium/webdriver/remote/”, line 321, in execute

File “/Users/Manu/.pyenv/versions/3.8.7/lib/python3.8/site-packages/selenium/webdriver/remote/”, line 242, in check_response

raise exception_class(message, screen, stacktrace)

selenium.common.exceptions.SessionNotCreatedException: Message: Expected browser binary location, but unable to find binary in default location, no ‘moz:firefoxOptions.binary’ capability provided, and no binary flag set on the command line

Ran 1 test in 1.839s

FAILED (errors=1)


I am not sure what is going wrong and why? Thanks in advance.