Managing libraries: three questions

Projects Programming
1

Most IDE error reports include messages about library candidates that:

(a) were not used; they are often in \AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6\libraries\

(b) were used, usually those in \SKETCHES\Libraries\

Q1: Will the unused library always be either the same or an earlier version? (I always promptly respond to IDE messages that there are some Updatable libraries, if that's relevant.)

Q2: Could the unused library therefore be safely deleted from its PC folder? Not that I would necessarily want to, but it would presumably speed up sketch start-up time and shorten error reports?

Q3: IDE 1.8.19 > Manage Libraries > Type > Installed shows many libraries that I have not knowingly installed. Checking the first couple confirms that the files do exist, but as you see they are not located in my SKETCHES\libraries folder. I have always assumed that to be what 'Installed' meant.

esplora
C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.57.0_x86__mdqgnx93n4wtt\libraries\Esplora\src\Esplora.h
C:\Program Files (x86)\Arduino\libraries\Esplora\src\Esplora.h


bridge
C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.57.0_x86__mdqgnx93n4wtt\libraries\Bridge\src\Bridge.h
C:\Program Files (x86)\Arduino\libraries\Bridge\src\Bridge.h

What am I missing here?

2

Libraries in branches of the Arduino15\packages folder are specific to particular processors, hence "avr" in your example. They are installed when you install a board package

If you have any other boards installed then take a look at the various branches below Arduino15\packages\hardware

Libraries in the sketchbook/libraries folder have been installed by the user and may or may not relate to particular boards

Library versions have nothing to do with the location of the library files. The compiler reports what it finds and then decides which is the appropriate library to use based on the board being used

It is quite possible to have two board specific libraries named say wibble.h but for them to be different due to the different resources available on different boards

My advice would be to leave well alone

3

Thanks, will do.