feat: expose task's exit code to env var 'DEFER_EXIT_CODE'

[dorimon-1]

Issue: #1484

Exposes environment variable DEFER_EXIT_CODE once a task is finished, to allow you to use it in defer statements.
In case there was an error (exit code != 0), it wont be overridden by a successful task, but it will be overridden when a different task fails with a different code.

[pd93]

Looks good to me. Thanks!

[andreynering]

Hi @dorimon-1. Thanks for your pull request, it is much appreciated!

I'm requesting changes EXIT_CODE should be a regular variable and not an environment variable. This would make it consistent with the other special variables.

[dorimon-1]

Hi @dorimon-1. Thanks for your pull request, it is much appreciated!

I'm requesting changes EXIT_CODE should be a regular variable and not an environment variable. This would make it consistent with the other special variables.

Hi, thanks for your comment.
I have made those changes, hope you see them fit

[danilobuerger]

@andreynering @pd93 any chance to get this merged?

[dorimon-1]

Also fixed conflicts and updated docs with the current standard

[andreynering]

Hey @dorimon-1!

There were further changes required for this to work as desired. I did those changes on #1762 and just merged it.

Basically, we neede to make that variable as scoped as possible, i.e., available only to that specific defer: command and not globally.