Cygwin startup configuration is controlled by Windows environment variable CYGWIN. Not populating Cygwin PATH from Windows PATH avoids confusion from Windows programs being used instead of Cygwin programs. Set Windows environment variable:
will result in a basic Cygwin PATH like:
Look inside Cygwin “/etc/profile” for more environment variables that may be of interest.
NOTE: all Windows environment variables are imported by Cygwin. Override these variables in ~/.profile or scripts if desired.
Related: don’t populate WSL PATH from Windows PATH.