/usr/bin/env: ‘python’: No such file or directory

[Ilmu011]

Describe the bug When I try to launch the endpoint, I get an error "/usr/bin/env: ‘python’: No such file or directory" and the process dies.

I am not familiar with python, but eventually figured out that the "shebang line" in the default_server_endpoint.py script is causing the issue. A common problem for shebang related issues seems to be with UNIX line endings, but even after applying the "dos2unix" command on the script file, the problem still persisted.

To Reproduce Steps to reproduce the behavior:

1. Setup the ROS TCP Endpoint package in the catkin workspace
2. Launch the "endpoint.launch" Launch-File

Console logs / stack traces

roslaunch src/ros_tcp_endpoint/launch/endpoint.launch 
... logging to /home/ilmu011/.ros/log/1c302e54-1a46-11ed-b94a-d1992999f350/roslaunch-ubuntu20-19246.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://ubuntu20:36939/

SUMMARY
========

PARAMETERS
 * /rosdistro: noetic
 * /rosversion: 1.15.14
 * /unity_endpoint/tcp_ip: 0.0.0.0
 * /unity_endpoint/tcp_port: 10000

NODES
  /
    unity_endpoint (ros_tcp_endpoint/default_server_endpoint.py)

ROS_MASTER_URI=http://localhost:11311

process[unity_endpoint-1]: started with pid [19260]
/usr/bin/env: ‘python’: No such file or directory
[unity_endpoint-1] process has died [pid 19260, exit code 127, cmd /home/ilmu011/Desktop/fusionws/src/ros_tcp_endpoint/src/ros_tcp_endpoint/default_server_endpoint.py __name:=unity_endpoint __log:=/home/ilmu011/.ros/log/1c302e54-1a46-11ed-b94a-d1992999f350/unity_endpoint-1.log].
log file: /home/ilmu011/.ros/log/1c302e54-1a46-11ed-b94a-d1992999f350/unity_endpoint-1*.log
all processes on machine have died, roslaunch will exit
shutting down processing monitor...
... shutting down processing monitor complete
done

Expected behavior It should work

Environment:

• Unity Version: (should be irrelevant, but it's 2021.3.4f1)
• Unity machine OS + version: Ubuntu 20.04
• ROS machine OS + version: Ubuntu 20.04, ROS Noetic
• ROS–Unity communication: (none yet... also not using docker)
• Branch or version: main

[Ilmu011]

This stackoverflow post solved my problem.

I just installed a package called "python-is-python3" via sudo apt install python-is-python3