Enhancement: Add environment variable to set the kpm output information level.

[zong-zhe]

Enhancement

kpm needs to increase the output information content to facilitate debugging and problem positioning, for users, some content needs to be disabled to optimize the user experience. Therefore, a switch is needed to adjust the content of the output information.

1. Add an environment variable

Set the environment variable KPM_LOG_LEVEL=debug, to show more details for debugging.
Set the environment variable KPM_LOG_LEVEL=info, to show normal message for users.
By default, KPM_LOG_LEVEL=info.

More details mainly includes some raw error information returned by library functions.

2. For future docs.

In the future design documents about displaying information, the label <debug_info> will be used to represent some uncontrollable information returned by third-party library functions.

[AkashKumar7902]

Hey @Peefy,
If this is still relevant, I would love to work on it. Can you please assign me this issue :)

[AkashKumar7902]

@zong-zhe
From what I analyzed from the code, when an error occurs and all the fields of kpmEvent struct is set then both msg and err is printed to the terminal because reporter.Fatal is called at the root file i.e. kpm.go ( i could be wrong here),

kpm/kpm.go

Line 56 in 194168a

reporter.Fatal(err)

type KpmEvent struct {
	errType EventType
	msg     string
	err     error
}

so, KPM_LOG_LEVEL=info would print only msg and KPM_LOG_LEVEL=debug would print both msg and err (that is happening currently).

Is my thought process correct ?

/cc @Peefy

[zong-zhe]

@zong-zhe From what I analyzed from the code, when an error occurs and all the fields of kpmEvent struct is set then both msg and err is printed to the terminal because reporter.Fatal is called at the root file i.e. kpm.go ( i could be wrong here),

kpm/kpm.go

Line 56 in 194168a

reporter.Fatal(err)

type KpmEvent struct {
	errType EventType
	msg     string
	err     error
}

so, KPM_LOG_LEVEL=info would print only msg and KPM_LOG_LEVEL=debug would print both msg and err (that is happening currently).

Is my thought process correct ?

/cc @Peefy

Hi @AkashKumar7902
Currently, we aspire for all diagnostic messages within kpm to be returned through KpmEvent, and be output to stdout or stderr using the built-in logWritter in KpmClient.

[The logWritter]（https://github.com/kcl-lang/kpm/blob/b197e0b33e4c34d3ec44283bc768014f903ac9c6/pkg/client/client.go#L34）

Therefore, you can create a custom structure and implement the io.Writer interface, allowing you to realize the feature of controlling output via the environment variable within your defined structure.

And ignore this, it will be deprecated. kpm cli will be replaced by the kcl cli.

kpm/kpm.go

Line 56 in 194168a

reporter.Fatal(err)

[Gmin2]

Is this still relevant ?
cc @zong-zhe @Peefy