Separate cmd output to return job-id to stdout, and helper text to stderr

[enricorotundo]

Currently

❯ bacalhau docker run ubuntu echo hello world
Job ID: 50422f95-ac90-4b1c-9ba6-39afb809ec53

To get the status of the job, run:
  bacalhau describe 50422f95-ac90-4b1c-9ba6-39afb809ec53

Needed

❯ bacalhau docker run ubuntu echo hello world
50422f95-ac90-4b1c-9ba6-39afb809ec53 # stdout
# stderr
To get the status of the job, run: # stderr
  bacalhau describe 50422f95-ac90-4b1c-9ba6-39afb809ec53 # stderr

This applies to:

• docker run
• probably create
• what else?

Thread https://filecoinproject.slack.com/archives/C02RLM3JHUY/p1664961242037189

[aronchick]

Ftw I don’t agree with this - stderr should only be used when it’s an error?

[wjam]

Outputting errors on stderr isn't a consistent thing, for example the output of HashiCorp's Vault CLI goes to stderr (e.g. see vault --help 2>/dev/null) where as Terraform goes to stdout. I remember running into this issue when doing some PowerShell on Windows a few years ago as PowerShell assumes that any tool which outputs to stderr must have failed rather than looking at the exit code.

Another example of a tool which mixes stdout & stderr is curl, which outputs the statistics to stderr so allowing users to safely redirect the output straight to a file.

[wjam]

One problem with mixing stdout & stderr would potentially be having the two outputs interleaved on the user's terminal

[lukemarsden]

yeah, conventionally stderr is used for user facing status / info messages as well as error messages

consult the exit code for whether or not there was an error

[lukemarsden]

fixed in https://github.com/filecoin-project/bacalhau/commit/7fc27cf1527cbfc6a86d469b0eda6c97a42f89f4

[lukemarsden]

reverted, reopening pending discussion with @aronchick tomorrow