gtdbtk doc help not available unless GTDBTK_DATA_PATH is set

[nick-youngblut]

This is a small, but annoying thing:

at least for GTDB-Tk v2.2.6, one cannot view the CLI help docs (e.g., gtdbtk classify_wf -h) without first setting a valid path to a GTDB-Tk database. Otherwise, instead of the help docs, the user gets:

================================================================================
                                     ERROR                                      
________________________________________________________________________________

          The 'GTDBTK_DATA_PATH' environment variable is not defined.           

            Please set this variable to your reference data package.            
           https://ecogenomics.github.io/GTDBTk/installing/index.html           
================================================================================

It would be helpful to evaluate GTDBTK_DATA_PATH after parsing the CLI args.

[pchaumeil]

Hello,
(This issue is similar to #491)

We will look to reimplement the GTDB-Tk logic so the basic options will not require to set GTDBTK_DATA_PATH.
This should be available in the next version.

[nick-youngblut]

Sorry for the re-post of an existing issue. I had just looked through the open issues prior to creating this one