$ arduino-cli version
arduino-cli.exe  Version: nightly-20220124 Commit: 530e671 Date: 2022-01-24T01:28:27Z

$ arduino-cli lib search --format jsonmini Arduino_MKRRGB
Updating index: library_index.json.gz downloaded ?  18677.76% 00m02ss
Updating index: library_index.json.sig downloaded
{"libraries":[{"name":"Arduino_MKRRGB","releases":{"1.0.0":{"author":"Arduino","version":"1.0.0","maintainer":"Arduino \u003cinfo@arduino.cc\u003e","sentence":"Allows you to draw on your MKR RGB shield.","paragraph":"Depends on the ArduinoGraphics library.","website":"http://github.com/arduino-libraries/Arduino_MKRRGB","category":"Display","architectures":["samd"],"types":["Arduino"],"resources":{"url":"https://downloads.arduino.cc/libraries/github.com/arduino-libraries/Arduino_MKRRGB-1.0.0.zip","archive_filename":"Arduino_MKRRGB-1.0.0.zip","checksum":"SHA-256:0c16c5db92467d65123b4fc16e0d3838d38c26da9137f2c50f3aa0cd17115b4d","size":7797,"cache_path":"libraries"},"provides_includes":["Arduino_MKRRGB.h"],"dependencies":[{"name":"ArduinoGraphics"}]}},"latest":{"author":"Arduino","version":"1.0.0","maintainer":"Arduino \u003cinfo@arduino.cc\u003e","sentence":"Allows you to draw on your MKR RGB shield.","paragraph":"Depends on the ArduinoGraphics library.","website":"http://github.com/arduino-libraries/Arduino_MKRRGB","category":"Display","architectures":["samd"],"types":["Arduino"],"resources":{"url":"https://downloads.arduino.cc/libraries/github.com/arduino-libraries/Arduino_MKRRGB-1.0.0.zip","archive_filename":"Arduino_MKRRGB-1.0.0.zip","checksum":"SHA-256:0c16c5db92467d65123b4fc16e0d3838d38c26da9137f2c50f3aa0cd17115b4d","size":7797,"cache_path":"libraries"},"provides_includes":["Arduino_MKRRGB.h"],"dependencies":[{"name":"ArduinoGraphics"}]}}],"status":1}

$ arduino-cli lib search --format jsonmini Arduino_MKRRGB | jq '.libraries[0].latest.version'
jq: error (at <stdin>:1): Cannot index number with string "libraries"
parse error: Invalid numeric literal at line 1, column 6

$ arduino-cli lib search --format json Arduino_MKRRGB | jq '.libraries[0].latest.version'
"1.0.0"

$ arduino-cli lib search --format yaml Arduino_MKRRGB
Updating index: library_index.json.gz downloaded ?  19660.80% 00m02ss
Updating index: library_index.json.sig downloaded
libraries:
- name: Arduino_MKRRGB
  releases:
    1.0.0:
      author: Arduino
      version: 1.0.0
      maintainer: Arduino <info@arduino.cc>
      sentence: Allows you to draw on your MKR RGB shield.
      paragraph: Depends on the ArduinoGraphics library.
      website: http://github.com/arduino-libraries/Arduino_MKRRGB
      category: Display
      architectures:
      - samd
      types:
      - Arduino
      resources:
        url: https://downloads.arduino.cc/libraries/github.com/arduino-libraries/Arduino_MKRRGB-1.0.0.zip
        archivefilename: Arduino_MKRRGB-1.0.0.zip
        checksum: SHA-256:0c16c5db92467d65123b4fc16e0d3838d38c26da9137f2c50f3aa0cd17115b4d
        size: 7797
        cachepath: libraries
      license: ""
      providesincludes:
      - Arduino_MKRRGB.h
      dependencies:
      - name: ArduinoGraphics
        versionconstraint: ""
  latest:
    author: Arduino
    version: 1.0.0
    maintainer: Arduino <info@arduino.cc>
    sentence: Allows you to draw on your MKR RGB shield.
    paragraph: Depends on the ArduinoGraphics library.
    website: http://github.com/arduino-libraries/Arduino_MKRRGB
    category: Display
    architectures:
    - samd
    types:
    - Arduino
    resources:
      url: https://downloads.arduino.cc/libraries/github.com/arduino-libraries/Arduino_MKRRGB-1.0.0.zip
      archivefilename: Arduino_MKRRGB-1.0.0.zip
      checksum: SHA-256:0c16c5db92467d65123b4fc16e0d3838d38c26da9137f2c50f3aa0cd17115b4d
      size: 7797
      cachepath: libraries
    license: ""
    providesincludes:
    - Arduino_MKRRGB.h
    dependencies:
    - name: ArduinoGraphics
      versionconstraint: ""
status: 1