RE: why does command echo \\\foobar print \\foobar

> But third, I still don't understand.  

As I say above, I cannot reproduce your third behavior.  Again, please
invoke Make with -d and show the results.


I know - because you are using Windows shell and Windows echo.  With Windows shell, and Cygwin echo, something is different.  Here you go:

C:\Temp>make -d -r foobar
GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for i386-pc-mingw32
find_and_set_shell path search set default_shell = C:/Tools/cygwin/bin/sh.exe
Reading makefiles...
Reading makefile `makefile'...
Updating makefiles....
 Considering target file `makefile'.
  Looking for an implicit rule for `makefile'.
  No implicit rule found for `makefile'.
  Finished prerequisites of target file `makefile'.
 No need to remake target `makefile'.
Updating goal targets....
Considering target file `foobar'.
 File `foobar' does not exist.
 Finished prerequisites of target file `foobar'.
Must remake target `foobar'.
echo \\\foobar
CreateProcess(C:\Tools\cygwin\bin\echo.exe,echo \\foobar,...)
Putting child 0x009edfc0 (foobar) PID 10414992 on the chain.
Live child 0x009edfc0 (foobar) PID 10414992
Main thread handle = 0x000007ac
\\foobar
Reaping winning child 0x009edfc0 PID 10414992
Removing child 0x009edfc0 PID 10414992 from chain.
Successfully remade target file `foobar'.