Compile with Arduino and get error

I compile a week old bugfix 2.0.x and everything is good.
I try to compile today's bugfix with my config files and get this:

Archiving built core (caching) in: C:\Users\Bill\AppData\Local\Temp\arduino_cache_39750\core\core_arduino_avr_mega_cpu_atmega2560_d162a8167a43ee5a27a03b44364657b0.a
Linking everything together...
"C:\\Users\\Bill\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-gcc" -w -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections,--relax -mmcu=atmega2560 -o "C:\\Users\\Bill\\AppData\\Local\\Temp\\arduino_build_235276/Marlin.ino.elf" "sketch\\Marlin.ino.cpp.o".............
..........."-LC:\\Users\\Bill\\AppData\\Local\\Temp\\arduino_build_235276" -lm
avr-gcc: error: CreateProcess: No such file or directory
Using library U8glib at version 1.19.1 in folder: D:\Users\Bill\Documents\Arduino\libraries\U8glib
exit status 1
Error compiling for board Arduino Mega or Mega 2560.

I deleted all the middle stuff .................
It will compile with the dist config files. When I put my configuration.h in I get the error. The adv file is original.
The config files are copy paste changes from the week old build - with some changes due to changes in the dist file

No sanity check errors or other errors except error RE libraries which also appear when it compiles.

I have no idea how to track this down. Do you?

"avr-gcc: error: CreateProcess: No such file or directory"

This is windows path limit.
the final linking command is to large for windows to handle (>32k characters)

Arduino ide does many thing wrong... that adds to this problem.
use vscode + platformio.

shorten all paths you can...
Move marlin to root of drive and rename to M

If you insist on using arduino ide move the temp build location directory to something short eg. create a T in root directory and set that as your build path.
"You can add a build.path entry to your Arduino IDE preference file (open the preference dialog in the IDE and click on the preference file name). Close the IDE before opening and editing the file."

Lastly remove things from marlin your not using. such as unused HAL directories and extui (if your not using it)

Edited 1 time(s). Last edit at 06/17/2020 11:45PM by Dust.

I have loaded platformio but have been unsuccessful at getting anything working. Every time I open VSCODE it wants to install platformio and takes forever to finish. Then I can't figure out how to run a compile.

Why does it reinstall IO and take so long to do it?

OK, I just deleted all the files I don't use and it compiles.