How to check that a command wrote nothing to stderr

Drone Support
1

I’d like to add a step in my drone build that checks a command wrote nothing to stderr
For instance lein :deps tree
I tried to add the folllowing to the commands array

commands:
      - echo "validating deps" && [[ $$(lein deps :tree) == 0 ]]

But it doesn’t work, it causes an error in the shell

/bin/sh: 27: [[: not found

My build is here

2

this is because [[ is a bash builtin, but Drone uses sh

3

Oh. I see
How would one compare numbers is sh and tell drone to fail the command when the numbers are not equal?

4

you might have better luck on stackoverflow where you will find some true shell scripting experts. I am not sure about number comparison, but if you want to fail a build step you would exit 1 (or any exit code greater than zero).