compilation error when changing variable from char to String

Question

I have a code with these two lines:

  char handshakecode = "S"; // Capital S
  char receive;

The lines of code are placed in a separate void, and not setup or loop. When i change the two variables from char to String i get a error(complete error at bottom) when compiling to the arduino or verifying the code.

  String handshakecode = "S"; // Capital S
  String receive; 

When i snippes out partial code for just that particular void, it compiles fine, so it must be in combination with the rest of the code, which i have left out from this post at the moment.

Is this a known error or am I doing something wrong?

In function 'global constructors keyed to 65535_0_WFS_v0.3.ino.cpp.o':

lto1.exe: internal compiler error: Segmentation fault

Please submit a full bug report,

with preprocessed source if appropriate.

See http://gcc.gnu.org/bugs.html for instructions.

lto-wrapper.exe: fatal error: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.15.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avr-gcc returned 1 exit status

compilation terminated.

c:/program files/windowsapps/arduinollc.arduinoide_1.8.15.0_x86__mdqgnx93n4wtt/hardware/tools/avr/bin/../lib/gcc/avr/5.4.0/../../../../avr/bin/ld.exe: error: lto-wrapper failed

collect2.exe: error: ld returned 1 exit status

exit status 1 Error compiling for board Arduino/Genuino Mega or Mega 2560.

Answer 1

This bug is specific to the 5.4.0-atmel3.6.1-arduino2 version of avr-gcc used by Arduino AVR Boards 1.6.22 and newer. It has been reported here:

https://github.com/arduino/Arduino/issues/7949

Here's the workaround:

1. Tools > Board > Boards Manager
2. Wait for downloads to finish.
3. When you move the mouse pointer over "Arduino AVR Boards", you will see a "Select version" dropdown menu appear. Select "1.6.21".
4. Click "Install".
5. Wait for installation to finish.
6. Click "Close".

Due to a bug, this workaround doesn't work with Arduino IDE 1.8.6, but it will work with any other version of the Arduino IDE.

If you have File > Preferences > Check for updates on startup checked, the Arduino IDE may occasionally notify you that a new version of Arduino AVR Boards is available, you'll need to refrain from updating back to the new Arduino AVR Boards version, otherwise you'll be back to seeing the segmentation fault error again.