Use the correct library when a relative path is passed as --library value

[MatteoPologruto]

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What kind of change does this PR introduce?

Code imperfection fix

What is the current behavior?

Compiling an example of a manually downloaded library fails if the command is executed inside the examples directory and a relative path to the library itself is specified.

C:\Users\m.pologruto>arduino-cli lib uninstall ArduinoIoTCloud
Uninstalling [ArduinoIoTCloud@1.11.0]...

C:\Users\m.pologruto>cd Downloads/ArduinoIoTCloud-1.11.0/examples/ArduinoIoTCloud-Basic

C:\Users\m.pologruto\Downloads\ArduinoIoTCloud-1.11.0\examples\ArduinoIoTCloud-Basic>arduino-cli compile -b arduino:samd:nano_33_iot --library ../../
...
...
Error during build: CreateFile ..\..\..\src\ArduinoIoTCloud.cpp: The system cannot find the path specified.

If the same library is installed with lib install, the library is picked from the Sketchbook's libraries directory.

What is the new behavior?

If the relative path to a library is correct, that library will be chosen over other instances of it.

Does this PR introduce a breaking change, and is titled accordingly?

No

[codecov]

Codecov Report

Patch coverage: 40.00% and project coverage change: -0.09 ⚠️

Comparison is base (a9729db) 62.56% compared to head (a45c362) 62.47%.

❗ Current head a45c362 differs from pull request most recent head 04f71b0. Consider uploading reports for the commit 04f71b0 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2126      +/-   ##
==========================================
- Coverage   62.56%   62.47%   -0.09%     
==========================================
  Files         231      231              
  Lines       19610    19599      -11     
==========================================
- Hits        12269    12245      -24     
- Misses       6238     6250      +12     
- Partials     1103     1104       +1     

Flag	Coverage Δ
unit	62.47% <40.00%> (-0.09%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
commands/compile/compile.go	71.10% <40.00%> (-0.72%)	⬇️

... and 12 files with indirect coverage changes

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[per1234]

There is no need to bundle the entire ArduinoIoTCloud library as test data. You can use a minimal library instead:

FooLib.zip

The only requirements for the test data:

• A sketch that contains an #include directive.
• A library that:
  • contains a header file with name matching the #include directive in the sketch
  • contains at least one source file (e.g., FooLib.cpp)

[per1234]

Thanks Matteo!