Assembler
ASMOPTIONS={<option>}
<option>: Assembler command-line option
If this environment variable is set, the Assembler appends its contents to its command line each time a file is assembled. It can be used to globally specify certain options that should always be set, so you do not have to specify them each time a file is assembled.
Options enumerated there must be valid assembler options and are separated by space characters.
ASMOPTIONS=-W2 -L
Assembler Options chapter