[FS#589] curl --capath not supported on mbedtls but was supported on polarssl

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Federico Capoano (nemesisdesign) 

Attached to Project - LEDE Project
Summary - curl --capath not supported on mbedtls but was supported on polarssl
Task Type - Bug Report
Category - Packages
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Medium
Priority - Very Low
Reported Version - lede-17.01
Due in Version - Undecided
Due Date - Undecided
Details -  - Device problem occurs on: any
 - Software versions: LEDE 17.01 (compiling from the dedicated branch)
 - Steps to reproduce: try using --capath with the default curl
   
I hit something that seems like a regression to me.

In a little program named [[https://github.com/openwisp/openwisp-config|openwisp-config]], we are using the --capath
argument, when switching - as was widely suggested - from polarssl to
mbedtls, we noticed curl cannot use the capath argument anymore.

There's also a thread in the forum here:
https://forum.lede-project.org/t/capath-not-supported-by-libcurl-with-mbedtls-support/947/8

I would like to ask 2 questions

 1. is it's desired behaviour or a regression?
 2. if it's not a regression, what's an alternative way to tell curl and or wget to find certificates? Can we document this best practice?

Thx in advance
Federico

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=589