Arduino Ide 1.8.12/13
Marlin 2.0.5.4
Kubuntu 18.04
Ramps 1.4
Mega 2560

Trying to compile Marlin 2.0.5.4, I ran into a problem. Just tested 2.0.6, same problem.
Searches have not resulted in finding a solution.

When configuring E0_AUTO_FAN_PIN and E1_AUTO_FAN_PIN for pin 5, the compiler ends in a loop, eating all memory when configuring 2 EXTRUDERS and SWITCHING_NOZZLE using servo nr. 1
No errors shown.

Testing after unpacking marlin 2.5.4 and just editing the Configuration.h and Configuration_adv.h with the
settings shown below, the problem appears.

Looks like it goes wild when compiling module/temperature.cpp.

If the thread compiling module/temperature.cpp is killed, the compiling finishes.
Otherwise the PC eventually freezes, out of memory!


The configuration has been taken from marlin 1.1.6 where there are no configuration problems.
Most likely, I am overlooking something, but fail to see it.

Configuration.h changes:

// Choose the name from boards.h that matches your setup
#ifndef MOTHERBOARD
  #define MOTHERBOARD BOARD_RAMPS_14_EEB  
#endif

// @section extruder

// This defines the number of extruders
// :[1, 2, 3, 4, 5, 6, 7, 8]
#define EXTRUDERS 2  
...
#define SWITCHING_NOZZLE  
...
#define SWITCHING_NOZZLE_SERVO_NR  1 //Need to use the pins for servo one 
...
#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_1 1
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_3 0
#define TEMP_SENSOR_4 0
#define TEMP_SENSOR_5 0
#define TEMP_SENSOR_6 0
#define TEMP_SENSOR_7 0
#define TEMP_SENSOR_BED 1
#define TEMP_SENSOR_PROBE 0
#define TEMP_SENSOR_CHAMBER 0
...
#define DISTINCT_E_FACTORS

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 4000, 500, 500 }

#define DEFAULT_MAX_FEEDRATE          { 300, 300, 5, 25, 25 }

#define DEFAULT_MAX_ACCELERATION      { 3000, 3000, 100, 10000, 1000 }

...
#define NUM_SERVOS 2  // Servo index starts with 0 for M280 command
...
#define SERVO_DELAY { 300 }

Configuration_adv.h changes:

#define E0_AUTO_FAN_PIN 5
#define E1_AUTO_FAN_PIN 5
#define E2_AUTO_FAN_PIN -1
#define E3_AUTO_FAN_PIN -1
#define E4_AUTO_FAN_PIN -1
#define E5_AUTO_FAN_PIN -1
#define CHAMBER_AUTO_FAN_PIN -1

#define EXTRUDER_AUTO_FAN_TEMPERATURE 50
#define EXTRUDER_AUTO_FAN_SPEED 255   // 255 == full speed
#define CHAMBER_AUTO_FAN_TEMPERATURE 30
#define CHAMBER_AUTO_FAN_SPEED 255

Last lines in the Arduino Ide output window up to and including temperature.cpp:

/home/cbp/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega2560 -DF_CPU=16000000L -DARDUINO=10813 -DARDUINO_AVR_MEGA2560 -DARDUINO_ARCH_AVR -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/cores/arduino -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/variants/mega /tmp/arduino_build_927596/sketch/src/module/stepper/indirection.cpp -o /dev/null -DARDUINO_LIB_DISCOVERY_PHASE
/home/cbp/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega2560 -DF_CPU=16000000L -DARDUINO=10813 -DARDUINO_AVR_MEGA2560 -DARDUINO_ARCH_AVR -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/cores/arduino -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/variants/mega /tmp/arduino_build_927596/sketch/src/module/stepper/trinamic.cpp -o /dev/null -DARDUINO_LIB_DISCOVERY_PHASE
/home/cbp/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega2560 -DF_CPU=16000000L -DARDUINO=10813 -DARDUINO_AVR_MEGA2560 -DARDUINO_ARCH_AVR -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/cores/arduino -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/variants/mega /tmp/arduino_build_927596/sketch/src/module/stepper.cpp -o /dev/null -DARDUINO_LIB_DISCOVERY_PHASE
/home/cbp/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega2560 -DF_CPU=16000000L -DARDUINO=10813 -DARDUINO_AVR_MEGA2560 -DARDUINO_ARCH_AVR -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/cores/arduino -I/home/cbp/.arduino15/packages/arduino/hardware/avr/1.8.3/variants/mega /tmp/arduino_build_927596/sketch/src/module/temperature.cpp -o /dev/null -DARDUINO_LIB_DISCOVERY_PHASE

Here the compiling thread was killed and the compiling ends:
Error while detecting libraries included by /tmp/arduino_build_927596/sketch/src/module/temperature.cpp
...
Sketch uses 62828 bytes (24%) of program storage space. Maximum is 253952 bytes.
Global variables use 2699 bytes (32%) of dynamic memory, leaving 5493 bytes for local variables. Maximum is 8192 bytes.