Document how to parse verbose messages to report equivalent GMT commands

Description of the desired feature

Sometimes we may need the equivalent GMT commands. For example,

1. some PyGMT issues are actually due to upstream GMT bugs (https://forum.generic-mapping-tools.org/t/829). When we open a GMT bug, we need the equivalent bash script
2. currently, how PyGMT works is a little fragile. Any unknown arguments are directly passed to GMT. See a bug report #256. The error messages are really confusing. But if the equivalent CLI commands are printed out, it would be much easier to understand why it doesn’t work as expected.

GMT already provides 7 verbosity levels by the -V option. The 7 verbosity levels (higher levels add more messages) are:

q < e < w < t < i < c < d

Here I propose to add one more verbosity level, for example, verbose='p'. The verbosity level should be between q and e, i.e.,

q <   < e < w < t < i < c < d
    ^
    |
    p

If verbose='p' is used, they PyGMT should print the equivalent GMT command when calling the function call_module().

I only spent a few seconds to choose the character p and its verbosity level. So I’m open to better choices.

Are you willing to help implement and maintain this feature?

Yes, it should be easy to implement it in the call_module() function. Contributions are welcomed.

[seisman]

perhaps in our bug report template

I don’t think users need to know the trick when reporting bugs. Perhaps better to document it in CONTRIBUTING.md.

[PaulWessel]

Sure, and actually, we know if we are called from externals (API->external is true) so we could print command when it makes sense.