I have no problem on my Chromebook with Debian linux using;
{
"Command": "XRunAndWait",
"Target": "/usr/bin/python3 ",
"Value": "/home/support/z.py",
"Description": "python script needs explicit file paths"
},
{
"Command": "store",
"Target": "${!xrun_exitcode}",
"Value": "strng",
"Description": ""
},
{
"Command": "echo",
"Target": "Python script exit code: ${strng}",
"Value": "",
"Description": ""
}
If your getting an error code = 1 uivision is not finding your python executable or script