As a workaround for known segmentation fault problems with the compiler (avr-gcc 5.4.0-atmel3.6.1) associated with the 1.6.22/23 avr board manager versions, I reverted to board version 1.6.21 using the board manager in Visual Micro.  Subsequently I (well, not me, but a knowledgeable person on the Arduino forum) was able to determine conclusively from a verbose compiler output that the Arduino IDE was indeed using V1.6.21 and the v4.9.2-atmel3.5.4-arduino2 compiler.

However, that same person was also able to show conclusively that when the same project was compiled in the VS/VM environment, VM still used the avr-gcc 5.4.0-atmel3.6.1 compiler associated with 1.6.22/23.  I have since checked and double-checked that the VM board manager dialog shows that board manager V1.6.21 is installed, but clearly VM isn't honoring my board manager version reversion from 1.6.23 to 1.6.21.

For all the gory details, see http://forum.arduino.cc/index.php?topic=577826.new#new

Any thoughts?

Frank

Tim,

I'm sorry, but I don't understand.  The C:\Users\Frank\AppData\Local\arduino15\packages folder is what the Arduino IDE uses to compile with gcc v4.9.2.

\4.9.2-atmel3.5.4-arduino2/bin/avr-gcc"  

so if I remove it, then both the Arduino IDE and the VS/VM environment compile with 5.4.0, which is the one with the segmentation fault bug.

"C:\Program Files (x86)\Arduino\hardware\tools\avr\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 -DVM_DEBUG_BREAKPAUSE -DVM_DEBUGGER_TYPE=VM_DEBUGGER_TYPE_HARDWARESERIAL -DVM_DEBUGGER_TYPE_MS430_SERIAL_=19 -DVM_DEBUGGER_TYPE_SERIALUSB=18 -DVM_DEBUGGER_TYPE_USBAPI=17 -DVM_DEBUGGER_TYPE_NET_UDP=16 -DVM_DEBUGGER_TYPE_HARDWARESERIAL3=15 -DVM_DEBUGGER_TYPE_HARDWARESERIAL2=14 -DVM_DEBUGGER_TYPE_HARDWARESERIAL1=13 -DVM_DEBUGGER_TYPE_CDCSerialClass=12 -DVM_DEBUGGER_TYPE_COSA=11 -DVM_DEBUGGER_TYPE_Uart=10 -DVM_DEBUGGER_TYPE_NET_CONSOLE=9 -DVM_DEBUGGER_TYPE_TTYUART=8 -DVM_DEBUGGER_TYPE_USBSERIAL=7 -DVM_DEBUGGER_TYPE_USART=6 -DVM_DEBUGGER_TYPE_UART=5 -DVM_DEBUGGER_TYPE_TEENSY=4 -DVM_DEBUGGER_TYPE_USB=3 -DVM_DEBUGGER_TYPE_FASTSERIAL=2 -DVM_DEBUGGER_TYPE_SOFTWARESERIAL=1 -DVM_DEBUGGER_TYPE_HARDWARESERIAL=0 -DVM_DEBUG_BANDWIDTH_THROTTLE_MS=50 -DVM_DEBUG_ENABLE=1 -DVM_DEBUG   -DF_CPU=16000000L -DARDUINO=10807 -DARDUINO_AVR_MEGA2560 -DARDUINO_ARCH_AVR -I"C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" -I"C:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\mega" -I"C:\Program Files (x86)\Arduino\libraries\Stepper\src" -I"c:\program files (x86)\microsoft visual studio\2017\community\common7\ide\extensions\sivbitce.zrh\Micro Platforms\default\debuggers\VM_DBG" -I"c:\program files (x86)\microsoft visual studio\2017\community\common7\ide\extensions\sivbitce.zrh\Micro Platforms\default\debuggers\VM_DBG\utility" "c:\program files (x86)\microsoft visual studio\2017\community\common7\ide\extensions\sivbitce.zrh\Micro Platforms\default\debuggers\VM_DBG\VM_DBG.cpp" -o "nul" 

Right now, Arduino IDE compiles with 4.9.2 as desired, but the VS/VM environment is still using 5.4.0, even though the C:\Users\Frank\AppData\Local\arduino15\packages folder points to 1.6.21 -> gcc 4.9.2

what am I missing?  Please speak sloooooolllyy, as I'm not very smart. 

Frank