Fix python_setup/install_tool.sh when python2 not present

[cdivitotawela]

Fix for #996

When the script executed on a runner which does not have python2, script incorrectly execute the code inside the if condition. This script runs using /bin/sh in Ubuntu and cause the problem. Fix for this issue to use different syntax in output redirection.

Issue is reproduced using running the job on Ubuntu container. Fix also verified in the action https://github.com/cdivitotawela/codeql-issue/actions/runs/2038530172

Tested using action file https://github.com/cdivitotawela/codeql-issue/blob/main/.github/workflows/investigate.yaml

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows. https://github.com/cdivitotawela/codeql-issue/actions/runs/2038530172
• Confirm the readme has been updated if necessary.
• Confirm the changelog has been updated if necessary.

[RasmusWL]

Thanks. I guess I did not confirm that the command -v worked as intended back then. I have been able to reproduce with the code below (on Ubuntu 21.10)

#!/bin/sh

if command -v nonexistingcommand &> /dev/null; then
    echo "old true"
else
    echo "old false"
fi

if command -v nonexistingcommand > /dev/null 2>&1; then
    echo "new true"
else
    echo "new false"
fi

which outputs

old true
new false

I can't say I fully understand this (in particular what the old version actually did), but thanks for the fix 💪

[edoardopirovano]

Looks good to me too, thanks for the fix!