Improve reporting of pipeline with wrong configuration

[olblak]

Improve reporting of pipeline with wrong configuration

Fix #552
This pull request allows to better identify which pipeline is failing due to a bad configuration.
Now It would show

+++++++++++
+ PREPARE +
+++++++++++

Loading Pipeline "updatecli/updatecli.d/golang.yaml"
Loading Pipeline "updatecli/updatecli.d/updatecli.yaml"
Loading Pipeline "updatecli/updatecli.d/venom.yaml"
ERROR: failed loading pipeline(s)
	* "updatecli/updatecli.d/golang.yaml" - scms ID "default2" referenced by pullrequest ID "default", doesn't exist
	* "updatecli/updatecli.d/updatecli.yaml" - scm id "default222" doesn't exist

instead of the old

+++++++++++
+ PREPARE +
+++++++++++

Loading Pipeline "updatecli/updatecli.d/golang.yaml"
Validating ""
Validating "GOLANG.YAML"
ERROR: ✗ scms ID "default2" referenced by pullrequest ID "default", doesn't exist
ERROR: Continuing and trying to go as far as possible

Test

To test this pull request, we needs updatecli configuration with wrong content and good content.

cp <to_package_directory>
go test

This pullrequest introduces a behavior change during the "prepare" stage.
Previously , it would just try to load as much configuration as possible and clone as much git repository as possible without failing. But now we exit if we couldn't load any pipeline or if something wrong happened with one of the git clones.

Additional Information

Tradeoff

Potential improvement

Implement the same behavior for git clones where it tries to clones as much repository as possible

[dduportal]

Fine for me, but proposed improvement around the switch by asserting on the error's type.

It's not blocking but as soon as there is an else it's a smell: thanks for commenting as it helps to maintain this code (unless there is a unit test to help other maintainers than the one whom wrote the initial conditions).