precompiling a library and using it

[beetryx_wolf]

hi all,
I created a simple library example that prints some messages according to a some analogue readings, im using the ESP32 microcontroller.
now im trying to precompile the library and use it's " . a " generated file. i followed the explanation of Mr
pert in this previous topic. as a resume, i compiled a new sketch in which i just included my library:

#include <mylibrary.h>
void setup() {
  // put your setup code here, to run once:
}
void loop() {
  // put your main code here, to run repeatedly:
}

when i compiled the example code, im supposed to have a "dot-a" file but i only got .d and .o files in "C:\Users\ghomr\AppData\Local\Temp\arduino_build_941257/mylibrary.ino.elf"
so i couldn't continue his explanation so,
Can any one help me on that?
Am i missing something to not got the .a file ? can you guide me to recompile and use the Library?
Thank you!

[pylon]

now im trying to precompile the library and use it's " . a " generated file.

Why? This is rather useless in the Arduino environment.

[beetryx_wolf]

update: i generated mylibrary.a file succesfully,
i put it at my library/src/esp32/ as libmylibrary.a
when i compile the example its shown:
"Error compiling for board ESP32 Dev Module."
what's wrong ?

[UKHeliBob]

its shown:
"Error compiling for board ESP32 Dev Module."

Is that the full error message ?