NMAKE Fatal Error U1100

macro 'macro-name' is illegal in the context of batch rule 'rule-name'

NMAKE generates this error when the command block of a batch-mode rule directly or indirectly references a special file macro that isn't $<.

$< is the only allowed macro for batch-mode rules.

For more information about NMAKE macros in batch rules, see Special NMAKE macros.