please support file: protocol for index files and platform/tools components

[PeterSommerlad]

Bug Report

Current behavior

$ arduino-cli core list

Error updating index: downloading index file://localhost//Users/sop/Arduino/Arduino-Cpp17/package_Cpp17AVR_index.json: Get "file://localhost//Users/sop/Arduino/Arduino-Cpp17/package_Cpp17AVR_index.json": unsupported protocol scheme "file"

Expected behavior

Like the Arduino IDE arduino-cli should support the file: for developing cores and platforms locally. Always having to upload/download or run a local web server is time consuming.

Environment

• CLI version (output of arduino-cli version):
  arduino-cli Version: 0.10.0 Commit: ec5c3ed

• OS and platform:
  Darwin Kernel Version 18.7.0: Mon Feb 10 21:08:45 PST 2020; root:xnu-4903.278.28~1/RELEASE_X86_64 x86_64 i386
  (Macos Mojave)

Additional context

I am working on a new AVR and ARM core with more modern C++17 internals. So far on ARM things look promising wrt code size and improved type safety.

[silvanocerza]

This is solved by #1098, closing.

[cjhdev]

This issue was not completely resolved in #1098

The index file contains package definitions, and each definition has a URL field.
The fix was applied to the index file URL, but not to the package URLs within the index file.

I have confirmed that the legacy IDE supports file URLs in the package definitions.

Should this issue be reopened?